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Cole-Greer pushed a commit to branch master
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The following commit(s) were added to refs/heads/master by this push:
new ad8e7e5d0b Add THREAT_MODEL.md + SECURITY.md and wire AGENTS.md
(security-model discoverability) (#3449)
ad8e7e5d0b is described below
commit ad8e7e5d0b2bfb30dd4abedd2231df92fabc05bf
Author: Jarek Potiuk <[email protected]>
AuthorDate: Sat Jul 11 03:26:50 2026 +0200
Add THREAT_MODEL.md + SECURITY.md and wire AGENTS.md (security-model
discoverability) (#3449)
Introduces a threat model document covering trust boundaries,
in-scope/out-of-scope items, and known non-findings Adds
SECURITY.md pointing to it, and wires AGENTS.md so the
AGENTS.md -> SECURITY.md -> THREAT_MODEL.md discoverability chain
resolves. Documentation only; no code or behavior changes.
Assisted-by: Claude Code:claude-opus-4-8 Claude Code:claude-fable-5
---------
Co-authored-by: Ken Hu <[email protected]>
Co-authored-by: Cole Greer <[email protected]>
---
AGENTS.md | 6 +
SECURITY.md | 30 +++
THREAT_MODEL.md | 554 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 590 insertions(+)
diff --git a/AGENTS.md b/AGENTS.md
index 0768139845..24d1038acc 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -100,3 +100,9 @@ These rules apply to any AI/IDE assistant operating on this
repository.
1. Prefer no change over an unsafe or speculative change.
2. Ask for clarification.
+
+## Security
+
+For Apache TinkerPop's threat model — trust boundaries, in-scope /
out-of-scope, the security properties
+the project does and does not provide, and known non-findings — see
[SECURITY.md](SECURITY.md), which
+points to [THREAT_MODEL.md](THREAT_MODEL.md). Consult it before triaging or
reporting security issues.
diff --git a/SECURITY.md b/SECURITY.md
new file mode 100644
index 0000000000..a22ee8eb3a
--- /dev/null
+++ b/SECURITY.md
@@ -0,0 +1,30 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements. See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership. The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied. See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# Security Policy
+
+Apache TinkerPop's threat model — the assumptions, trust boundaries, what is
in and out of scope, the
+security properties the project does and does not provide, and known
non-findings — is documented in
+[THREAT_MODEL.md](THREAT_MODEL.md). Please read it before reporting a security
issue.
+
+## Reporting a Vulnerability
+
+Please report security vulnerabilities privately following the
+[ASF security process](https://www.apache.org/security/) — email
+[[email protected]](mailto:[email protected]). Do not open public GitHub
issues for security reports.
diff --git a/THREAT_MODEL.md b/THREAT_MODEL.md
new file mode 100644
index 0000000000..d85dd1d450
--- /dev/null
+++ b/THREAT_MODEL.md
@@ -0,0 +1,554 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements. See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership. The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied. See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+
+# Apache TinkerPop — Threat Model
+
+## §1 Header
+
+- **Project:** Apache TinkerPop (`apache/tinkerpop`) — a graph computing
framework: the Gremlin query
+ language, the traversal machine, Gremlin Server (remote query execution),
the GraphSON and GraphBinary
+ wire serializers and the Gryo IO format, and the Gremlin Language Variants
(Java, Python, .NET, Go, JS).
+- **Scope of this model:** the **`apache/tinkerpop` monorepo**, active branch
`master`. The model focuses on
+ the network-facing and deserialization surfaces (see §2). Provider graph
databases that make use of
+ reference code are out of scope (§3).
+- **Version binding:** versioned with the project. A report against release
*x.y.z* is triaged against the
+ model as it stood at *x.y.z*, not against `HEAD`.
+- **Reporting cross-reference:** §8-property violations → report privately per
the ASF process
+ (`[email protected]`). §3 / §9 findings are closed citing this document.
+- **What TinkerPop is:** a graph computing framework for graph databases
(OLTP) and graph analytic systems
+ (OLAP). It **defines** a common interface/language (Gremlin) plus
protocols/APIs, and ships
+ production-ready reference implementations. This includes a reference
in-memory graph (TinkerGraph), Gremlin
+ Server, and the language variants (GLVs). Gremlin traversals run in one of
two environments. In
+ **embedded**, the caller runs traversals directly in their application via
`gremlin-core`. In **remote**,
+ Gremlin is sent over the wire (as a **script**) to a server that executes it.
+
+## §2 Scope and intended use
+
+- **Primary use:** TinkerPop runs in two environments (§1). In **embedded**,
the caller runs traversals in
+ its own JVM via `gremlin-core`, so there is no network trust boundary and
the caller owns the whole
+ surface. In **remote**, Gremlin is sent over the wire to a server. This
model focuses on the **remote**
+ case, where **Gremlin Server** is the main network-facing trust boundary.
Gremlin Server **is intended to
+ be deployable on the public internet**, but the shipped
`gremlin-server.yaml` is a getting-started/testing
+ config that **must not be deployed as-is**. A public or otherwise
untrusted-facing deployment is expected
+ to layer on TLS and an authenticator.
+- **Embedded surface.** Embedded has **no network, transport, auth, or
HTTP-protocol surface** (those exist
+ only with a server). It exposes the same input-consuming primitives as
remote, and only where the caller
+ feeds them untrusted data: the **`io()` readers** (GraphSON, Gryo, GraphML),
the **`gremlin-language`
+ parser** if untrusted strings are parsed, and **expensive steps** (e.g.
`regex`). The responsibility rules
+ are **identical to remote** because they attach to the primitive, not the
environment.
+- **Caller roles** (Gremlin Server is a network service):
+ - **remote client** — connects over HTTP/1.1, submits Gremlin as a
gremlin-lang string (or, if
+ `gremlin-groovy` is explicitly enabled, a Groovy script). Trust level
depends entirely on whether
+ the operator enabled authentication, authorization, and script
restrictions. Authentication is **off
+ in the shipped default** (`gremlin-server.yaml` has no `authentication`
block, and the default is
+ `AllowAllAuthenticator`).
+ - **application / provider** — runs `gremlin-core` directly, whether
embedded in its own process or as
+ Gremlin Server. A provider may also supply the
`Authenticator`/`Authorizer` implementations the server
+ runs. Trusted within the compile-time + configuration boundary.
+ - **operator** — runs Gremlin Server, controls `gremlin-server.yaml`,
serializers, auth, TLS, the script
+ engine configuration, and the host. Trusted for the instance.
+
+**Component-family table** *(in/out = in/out of this model)*:
+
+| Family | Entry point | Touches outside the process | In model? |
+| --- | --- | --- | --- |
+| **Gremlin Server** (`gremlin-server`) | HTTP/1.1 endpoint (gremlin-lang
string requests, GraphSON/GraphBinary serialization) | network (listens),
invokes the script engine + traversal machine | **In** |
+| **Script engine** (default `gremlin-lang`, optional `gremlin-groovy`) |
evaluates the request's script string | default parses only Gremlin (no code
execution). Optional Groovy runs supplied code in-process | **In**. The default
is a parser surface. Enabling `gremlin-groovy` is a non-default operator choice
whose RCE is by-design (§9) |
+| **Gremlin language parser** (`gremlin-language`) | ANTLR grammar for string
Gremlin (script-engine-free) | — | **In**, parser must not crash/hang/OOM on
malformed input, nor let a crafted string break out of a literal to inject
steps |
+| **GQL parser** (`gql-gremlin`) | ANTLR grammar for the GQL string of a
`match(String)` request | — | **In**, reference code active on the default
distribution (TinkerGraph registers it), with the same parser
robustness/integrity as `gremlin-language`. Non-executable if a provider
registers no declarative-match strategy (§3) |
+| **Core traversal machine + structure API** (`gremlin-core`) |
`GraphTraversal`, strategies, `Vertex`/`Edge` | filesystem (IO formats) |
**In** |
+| **Serialization** (`gremlin-core`/`gremlin-util`/`gremlin-shaded`) |
GraphSON + GraphBinary wire readers. Gryo (Kryo) is IO-format-only, not on the
wire | deserializes untrusted wire bytes. Gryo only reads IO/file bytes |
**In** (see §9) |
+| **Gremlin Language Variants** (Java `gremlin-driver`, `gremlin-python`,
`-dotnet`, `-go`, `-js`) | deserialize server responses | network (connect) |
**In**, response-deserialization robustness + TLS cert validation. Java shares
the JVM serializers. The others have own per-language deserializers not covered
by hardening the JVM server |
+| **Reference graph** (`tinkergraph-gremlin`) | in-memory graph, the **shipped
default graph**, with optional file persistence via the `io()` readers |
filesystem (persistence) | **In**, TinkerPop reference code on the default
reachable path, so a defect in unmodified TinkerGraph is `VALID` (§3). Loading
a persisted graph uses the same GraphSON/Gryo/GraphML readers (§6 IO surface).
A custom `graphFormat` reader is provider code (§3) |
+| **OLAP** (`gremlin-core`/`tinkergraph` computer, `hadoop-gremlin`,
`spark-gremlin`) | `GraphComputer`, remote-reachable when the operator
configures an OLAP-capable graph | network, filesystem, cluster | **In**,
reference code (incl. Hadoop/Spark modules). The third-party Hadoop/Spark
runtime + cluster config are out (§3) |
+| **`gremlin-console`** | local Groovy REPL. `:remote console` submits
**arbitrary Groovy scripts** to a server and deserializes responses. `:install`
loads plugins (credentials/hadoop/spark) via Grape | network (connects) | Local
REPL **Out** (operator-trusted). As a remote client, submitting arbitrary
Groovy = server-side RCE **by-design** (§9), subject to server auth.
Response-deserialization robustness + TLS cert validation **In** (like a GLV).
Plugins are operator-installed code in [...]
+| **`gremlint`** | client-side Gremlin formatter (parse-and-reprint, no query
execution); published as a library for integration into client applications. |
none (runs in the caller's browser/process) | **In**, valid surface for
security reports since it's a published, user-integrated library |
+| Test-only / example / build modules (e.g. `gremlin-test`,
`gremlin-examples`, `gremlin-tools`, `gremlin-annotations`) |
test/build/example code | — | **Out** *(see §3)* |
+
+## §3 Out of scope (explicit non-goals)
+
+- **Provider code and provider modifications to the reference code.**
TinkerPop ships production-ready
+ **reference code** (`gremlin-core`, `gremlin-server`, `tinkergraph-gremlin`,
etc.) that providers
+ are free to use in whole, in part, or not at all. The boundary is drawn by
**what code the defect
+ reproduces in**, not by where that code runs (provider code typically runs
in the same process as TinkerPop
+ code):
+ - **In-model:** a defect reproducible in **unmodified TinkerPop reference
code**, even when it is running
+ as part of a provider's product.
+ - **Out-of-model → route to the provider:** a defect that depends on the
**provider's own code or their
+ modifications** to the reference code, such as a modified
`Channelizer`/`GraphManager`, an
+ added request handler, their `Graph`/`GraphComputer` implementation, a
**`call()` service they register**
+ (`ServiceRegistry` is empty by default), or their
`Authenticator`/`Authorizer` decision logic.
+ - **Hard case (→ `MODEL-GAP`, §12/§13):** a defect that reproduces only
under a **mix** of reference and
+ provider code and cannot be cleanly attributed to either. This is not
silently dropped to the provider.
+ It triggers a joint determination and a §12 model revision.
+
+ Triage test: *is the defective code TinkerPop's?* A defect in unmodified
TinkerPop reference code is
+ in-model, whatever product or graph it runs inside. A defect that depends on
the provider's own code or
+ modifications is the provider's. If it genuinely can't be told, `MODEL-GAP`.
+- **The calling application's own authentication / authorization of its end
users.** TinkerPop has no
+ concept of the calling application's end users.
+- **Attackers who already control the host, the Gremlin Server process,
`gremlin-server.yaml`, or the
+ graph data directory.** They have the operator's authority by definition.
+- **Operator-configured code-execution/side-effect surfaces:** the Script I/O
Format (`ScriptInputFormat`/
+ `ScriptOutputFormat` run operator-supplied Groovy from HDFS) and
`EventStrategy` `MutationListener`
+ callbacks. The code comes from operator/provider config, not a remote
request (though a remote mutating
+ traversal can *trigger* an already-registered listener). Trusted-input.
*(documented — Script I/O Format;
+ `EventStrategy`)*
+- **Any test-only module, any example-only module, and build/distribution
tooling** as a production trust
+ surface (e.g. `gremlin-test`, `gremlin-examples`, `gremlin-tools`).
+- **Confidentiality of data in transit when the operator has not enabled TLS**
(see §10). TLS is **off by
+ default** (`ssl.enabled: false`), so the TLS posture is the operator's
deployment responsibility.
+- **`gremlin-javascript` client-side Gremlin parser / `GremlinTranslator`** —
a parse-and-reprint translator
+ (no query execution), off the request/response path, so not a network
surface. Its shipped consumers are
+ Gremlator (a browser SPA where the input is the user's own, affecting only
their own tab, like `gremlint`)
+ and `gremlin-mcp` (its untrusted-input robustness is the `gremlin-mcp`
surface's concern). As a library export, parsing caller-chosen input is the
+ consuming application's responsibility.
+- **`gremlin-mcp`** — a shipped MCP server that bridges an AI agent to a
Gremlin Server (a GLV-like client
+ plus an agent tool boundary). Findings route by the model's usual axis. A
**decision** (running it, what
+ graph it targets, what an agent may do through it) is the user's, so it is
out-of-model and documented as
+ trusted-environments-only. A **code defect** in `gremlin-mcp`, such as a
tool handler crashing/hanging/
+ OOMing on malformed input (an LLM can emit anything) or mishandling a server
response, is in-model like
+ any TinkerPop bug (§8).
+- **Client-side `RequestInterceptor` (GLV)** — a calling application can
register an interceptor to mutate
+ the outgoing HTTP request (the standard hook for auth/signing). What a
registered interceptor does, and a
+ bug within it, is the **calling application's** responsibility
(out-of-model), like any code it supplies.
+ The GLV correctly *running* registered interceptors (invoking them, in
order, without corrupting the
+ request) is TinkerPop code and **in-model**.
+
+## §4 Trust boundaries and data flow
+
+Data flow for a remote request. The `‖` marks the trust boundary, and
everything right of it runs on the server.
+
+```
+ TRUST BOUNDARY
+ calling app → GLV (build gremlin-lang ‖
+ string) → HTTP request ────────────────────▶ ‖ HTTP/1.1 decode
+ ‖ → authenticate →
deserialize request body
+ ‖ (GraphSON /
GraphBinary / JSON)
+ ‖ → authorize → execute
(gremlin-lang parser /
+ ‖ traversal machine) →
graph + storage / io() files
+ GLV ◀──────── deserialize response ──────────── ‖ → iterate results →
encode response
+```
+
+- Untrusted input crosses left-to-right at the boundary (request bytes). The
response path crosses
+ right-to-left back to the GLV (server-response bytes are untrusted from the
client's standpoint, §8).
+- The **embedded** environment has no boundary, since the caller runs
`gremlin-core` in-process (§2).
+- The **`io()` / file surface** feeds the graph/storage box from disk,
untrusted only if the caller loads
+ untrusted files (§6).
+
+- **Primary trust boundary: the Gremlin Server remote request surface.** Bytes
arriving over HTTP/1.1 are
+ untrusted, including the request line, headers, and the serialized request
body carrying the Gremlin
+ string. The script engine, traversal machine, and structure/storage layer
sit behind this boundary. HTTP/1.1
+ is the **only** transport (`HttpChannelizer`), so the **HTTP protocol layer
is itself a pre-auth surface
+ distinct from request-body deserialization**: the request line, headers,
chunked/streamed bodies, and
+ keep-alive connection handling must all be parsed per the HTTP/1.1
specification and must be safe against
+ malformed or maliciously crafted requests (§8 memory-safety covers it). No
crafted HTTP message, header, or
+ request sequence may crash, hang, exhaust, or gain unauthorized access to
the server. *(documented —
+ `HttpChannelizer`, remote endpoint)*
+- **The script-execution boundary (the highest-stakes one).** A string-based
request is evaluated by the
+ configured script engine. The shipped default is `GremlinLangScriptEngine`,
which parses **only Gremlin**
+ and is **not** a code-execution surface. An operator can instead configure
`gremlin-groovy`, which
+ evaluates arbitrary code: absent a configured sandbox / allow-list,
**evaluating an attacker-supplied
+ Groovy script is arbitrary code execution on the server**. That is inherent
to the general-purpose script
+ engine, not a bug, and enabling it is a non-default operator choice
(`BY-DESIGN` / out-of-model, §9). The
+ question for triage is whether a deployment enabled `gremlin-groovy`,
whether it restricted scripting
+ (allow-list, sandbox), and who is authorized to submit scripts. *(documented
— `gremlin-server.yaml`
+ default engine, `gremlin-applications.asciidoc` "Protecting Script
Execution")*
+- **The deserialization boundary.** GraphSON and GraphBinary readers parse
untrusted request bytes (and, on
+ the driver/GLV side, untrusted server-response bytes). Gryo is IO-only (not
on the wire). *(documented —
+ wire set is GraphSON + GraphBinary)*
+- **Reachability preconditions** (the test a triager applies first):
+ - A finding reachable only by submitting a **script** is in-model only
subject to the §9 ruling: if the
+ deployment allows scripting to the principal, server-side code execution
is by-design.
+ - A finding in the **Gremlin parser / traversal machine / deserializers**
reachable from a
+ client operating within its privileges (or pre-auth) is **in-model** for
memory-safety / bounded-
+ resource robustness.
+ - A finding requiring control of `gremlin-server.yaml` or host access is
**out-of-model: trusted-input**.
+
+## §5 Assumptions about the environment
+
+- **Runtime:** JVM (server, core, groovy, driver). The GLVs run on their
respective runtimes
+ (CPython, .NET, Go, Node).
+- **Deployment:** Gremlin Server is safe enough to run on the public internet
**once hardened** beyond the
+ shipped `gremlin-server.yaml`, at minimum with TLS plus an authenticator
(either built-in mechanism
+ suffices over TLS). The insecure getting-started default is a testing
convenience, not a supported
+ production posture. Realistically, a production deployment also layers a
provider's
+ `Authenticator`/`Authorizer` on top (no authorizer ships, see §5a), so
auth/authz is a **shared
+ responsibility**. The provider supplies the policy (the plugin
implementations), while Gremlin Server owns
+ the enforcement machinery that runs them on every request (§8).
+- **Filesystem:** the graph data / config directories are private to the
server process and not writable by
+ untrusted local users. Securing the host is the operator's responsibility,
and an attacker who can write
+ them already has the operator's authority (§3).
+- **Concurrency:** the standard request path is isolated per request
(thread-pool dispatch, per-request
+ script bindings), so one request should not affect another. Transactions are
the deliberate stateful
+ exception (§11b).
+- **What the server does to its host** (negative inventory): listens on
network ports; reads/writes its
+ configured graph + data directories; reads config; **executes supplied
Groovy when script requests are
+ enabled**; loads provider graph
+ implementations the operator configured.
+
+## §5a Build-time and configuration variants
+
+Knobs that change which security properties hold (Gremlin Server,
`gremlin-server.yaml`):
+
+- **Authentication** — `Authenticator` (username/password against a
credentials graph via
+ `SimpleAuthenticator`). Authentication is **off by default** (the shipped
`gremlin-server.yaml` has no
+ `authentication` block, and the default is `AllowAllAuthenticator`). The
built-in `SimpleAuthenticator`
+ mechanism is **secure enough for a public-internet deployment when combined
with TLS**. In practice,
+ though, deployments layer a provider's own `Authenticator` on top (e.g. SSO
/ bearer-token), so the
+ built-in is more often a baseline than the production mechanism.
*(documented — `SimpleAuthenticator`
+ ships; auth off by default)*
+- **Authorization** — an `Authorizer` SPI exists, but **no implementation
ships** with Gremlin Server (the
+ only one in-tree, `AllowListAuthorizer`, is a test example), so there is
**no meaningful authorization
+ control out of the box**, and providing it is expected to fall to the
provider. In-model only when
+ configured, and the default is none. *(documented —
`gremlin-applications.asciidoc` "Authorization":
+ no impl ships)*
+- **Restricting traversals via `TraversalStrategy`** — an
operator/`Authorizer` can constrain a
+ `GraphTraversalSource` with `ReadOnlyStrategy` (block mutations),
`SubgraphStrategy`/`PartitionStrategy`
+ (scope visible data / tenancy), and `VertexProgramRestrictionStrategy`
(restrict OLAP). These are **traversal-layer,
+ not storage-layer**: `PartitionStrategy` is bypassable via direct
`Vertex.property()`, and
+ `ReservedKeysVerificationStrategy` does not cover `mergeV`/`mergeE`. A
client can also remove an applied
+ strategy outright via `withoutStrategies()` unless an `Authorizer` denies it
(§9). In-model only when
+ pinned by a configured `Authorizer`. *(documented — `the-traversal.asciidoc`
"TraversalStrategy";
+ `gremlin-applications.asciidoc` "Authorization")*
+- **TLS/SSL** — configurable on the server connector, **off by default**
(`ssl.enabled: false` in the
+ shipped `gremlin-server.yaml`, enabled only in
`gremlin-server-secure.yaml`). Drives the
+ transport-confidentiality property (§9).
+- **Audit logging** — `enableAuditLog` records the authenticated user, remote
address, and gremlin query.
+ It is **off by default** (`false`, "for privacy reasons") and absent from
the shipped config, so a default
+ deployment keeps no attribution record (§9). *(documented —
`gremlin-applications.asciidoc` config table;
+ `Settings.enableAuditLog`)*
+- **Script execution restriction** — a script engine is only an
arbitrary-code-execution surface if it
+ evaluates a general-purpose language. The default `GremlinLangScriptEngine`
parses **only Gremlin** and can
+ neither evaluate arbitrary code nor run lambdas, so it has no such surface
to restrict. The restriction
+ controls (sandbox / compilation customizers / allow-list) apply to
`gremlin-groovy`, which is **not
+ enabled in the shipped configs**. (`LambdaRestrictionStrategy` exists but,
being a removable strategy,
+ is no real restriction against a client that can script, §9.) **Where
`gremlin-groovy`
+ is added it is unrestricted out of the box:** no shipped config configures a
sandbox or a lambda
+ restriction. The docs are explicit that TinkerPop offers no complete
out-of-the-box protection against
+ nefarious scripts. *(documented — `gremlin-applications.asciidoc`
"Protecting Script Execution", the sample
+ configs)*
+- **Enabled serializers** — wire set is GraphSON + GraphBinary. Gryo is
IO-format-only, not on the wire,
+ and defaults to a locked registration allow-list
(`registrationRequired=true`). Disabling that lock removes
+ the untrusted-input protection (§9). *(documented — sample configs,
`gremlin-applications.asciidoc`
+ "Serialization")*
+
+## §6 Assumptions about inputs
+
+Per-surface trust table:
+
+| Surface | Input | Attacker-controllable? | Caller/operator must enforce |
+| --- | --- | --- | --- |
+| Gremlin Server — script request | Gremlin (or, if `gremlin-groovy` is
enabled, Groovy) script text | **yes** (pre-auth if auth off) | auth; script
restriction / sandbox; who may script; traversal-step allow-list; resource
limits |
+| Gremlin Server — transaction id | server-generated UUID, echoed back by the
client on follow-up requests | **yes** (a client can present any id) | looked
up with no owning-user check, so any client presenting a valid id shares that
transaction (see §11b) |
+| Request deserialization (GraphSON / GraphBinary) | serialized bytes |
**yes** (pre-auth only when auth is off, see the ordering note below) |
robustness of the wire serializers |
+| Graph IO — Gryo/GraphSON/GraphML files (`io()` step, persistence, OLAP) |
on-disk / cluster bytes | only if the caller loads untrusted files | GraphSON,
locked Gryo (`registrationRequired=true`), and GraphML with the default XML
factory owe deserializer integrity. Unlocked Gryo and a caller-supplied
unhardened `XMLInputFactory` (XXE) are the caller's responsibility |
+| Gremlin string parser (`gremlin-language` ANTLR) | Gremlin string | **yes**
| parser robustness, no crash/hang/OOM on malformed input and no grammar
breakout / step injection (distinct from execution cost, §8/Q7) |
+| Any string the grammar accepts as an argument (e.g. a `regex` pattern) |
Gremlin string | **yes** | a grammatically valid string must not enable DoS
(e.g. ReDoS via a pathological pattern), the Q7 super-linear-amplification
carve-out (§8) |
+| GLV (client) — server response | serialized bytes from the server | yes if
the server is malicious/compromised, or a MITM (TLS off / cert not validated) |
response-deserialization robustness; TLS with cert validation |
+| `gremlin-server.yaml`, host, data dir | local | no — operator-trusted |
filesystem permissions |
+
+- **Pre-auth vs post-auth (ordering note):** "pre-auth" marks what an attacker
can reach **without valid
+ credentials**, which is what makes a defect there security-critical (§8).
Gremlin Server authenticates
+ **before** it deserializes the request body (§4 diagram): a request that
fails authentication is rejected
+ with its body still unparsed. On a deployment with an authenticator
configured, the body deserializers
+ are therefore a **post-auth** surface, reachable only by a client that
already holds valid credentials.
+ They are pre-auth only where auth is off (the shipped default). What remains
pre-auth on **every**
+ deployment is the HTTP protocol layer itself, since the request line,
headers, and body bytes must be
+ read and buffered (bounded by `maxRequestContentLength`) before the server
can even check credentials.
+ A deserializer bug is in-model either way. The ordering only sets its
severity. *(documented — §4 flow;
+ `HttpChannelizer` pipeline order)*
+- **Shape / rate:** Gremlin Server has per-request limits
(`evaluationTimeout`, `maxRequestContentLength`,
+ `maxParameters`, `maxWorkQueueSize`) and transaction bounds
(`idleTransactionTimeout`,
+ `maxTransactionLifetime`, `maxConcurrentTransactions`) but **no
traversal-depth or result-count cap**.
+ The bug-vs-capacity line is the §8 resource split. *(documented —
`gremlin-applications.asciidoc` config
+ table)*
+- **Script-cache growth (`gremlin-groovy` only):** with the opt-in Groovy
engine enabled, a client
+ submitting many distinct, unparameterized scripts grows the compiled-script
/ global-function cache toward
+ `OutOfMemoryError`. The operator mitigates by bounding
`classMapCacheSpecification` and preferring
+ parameterized scripts (the Q7 resource split, a documented remote DoS unless
bounded). The default
+ `GremlinLangScriptEngine` instead caches parsed traversals, off by default
and bounded when enabled, so it
+ carries no such growth.
+
+## §7 Adversary model
+
+- **Client → server (primary):** the highest-stakes surface (most code, most
exposure). A network client
+ that can reach the Gremlin Server port from within the deployment, either
**unauthenticated** (if auth is
+ off / pre-auth) or **authenticated with limited privileges**, trying to
execute code on the server (via
+ scripts), read/write graph data outside its intent, crash or exhaust the
server with malformed requests or
+ expensive traversals, or exploit a deserializer. *Capabilities:* can open
connections, send arbitrary
+ HTTP requests / scripts / serialized payloads, and supply large/malformed
input.
+- **Server → client:** a malicious or compromised server, or a network
attacker on the wire when TLS is off,
+ targeting a GLV through the response it returns: crafted response bytes to
crash/OOM/RCE the client, or
+ harvesting the credentials the client sends in its request (§8/§9).
+- **Untrusted input → embedded:** in the embedded environment there is no
network client, but untrusted data
+ can still reach an in-process `gremlin-core` primitive through the calling
application — an `io()` reader
+ fed an untrusted file, the `gremlin-language` parser fed an untrusted
string, or an expensive step fed a
+ crafted argument. The relevant robustness properties (§8) apply identically,
since they attach to the
+ primitive, not the environment (§2/§6).
+- **Out of scope:** anyone with operator/host/config control (already
authoritative). Also an attacker who
+ reaches a server left on the **insecure getting-started default** (no TLS,
no auth), which is an operator
+ hardening failure (§9/§10), not a code bug, though the pre-auth robustness
properties (§8) still apply to
+ the exposed surface. Side-channel/timing adversaries are **out of scope**.
*(maintainer —
+ public exposure of a hardened server is in scope, whereas exposure of the
insecure default is an operator
+ failure)*
+
+## §8 Security properties the project provides
+
+**Assets these properties defend (what is being protected):**
+
+- **Server availability** — the Gremlin Server process staying up under
malformed or pre-auth input.
+- **Server-side code-execution / host integrity** — not running attacker code
beyond what scripting/lambdas
+ grant by design (§9).
+- **Graph data confidentiality and integrity** — read/write/delete of the
graph, bounded by auth/authz and
+ traversal strategies (§5a/§9).
+- **Credentials** — the server-side credential store and the credentials a
client presents (§5a/§9).
+- **Client (GLV) integrity** — a client not harmed by hostile server responses.
+
+**Properties:**
+
+- **Enforcement of configured restrictions.** With an
`Authenticator`/`Authorizer` set, an
+ unauthenticated or unauthorized client cannot execute requests beyond its
grants (§11b transaction
+ sharing excepted). The same holds for restrictions living in server
configuration that no request can
+ touch: a *configured* script sandbox / compilation customizer / allow-list
must not be evadable from a
+ request. A restrictive `TraversalStrategy` (`ReadOnlyStrategy`,
`SubgraphStrategy`, ...) counts as a
+ configured restriction **only when an `Authorizer` denies its removal or
modification**, because the
+ Gremlin language itself lets a request remove strategies via
`withoutStrategies()` (§9). This is the §8
+ anchor for the "bypasses a *configured* restriction" rulings in §9/§11a.
*Violation symptom:* auth/authz bypass, or a request evading a
+ configured restriction. *Severity:* security-critical.
+- **Credential-store handling (when the built-in mechanism is used).** Where a
deployment uses
+ `SimpleAuthenticator` with the credentials graph, passwords are stored and
verified as BCrypt hashes,
+ never as plaintext. A provider's own `Authenticator` and credential store
are the provider's (§3).
+ *Violation symptom:* plaintext credential storage, or disclosure of stored
credential material to a
+ client. *Severity:* high.
+- **Memory / availability safety on the request + deserialization surface.**
Malformed or pre-auth input
+ (HTTP messages, Gremlin strings, serialized payloads) yields a clean error,
not a crash, OOM, hang, or
+ unbounded allocation of the server. This covers not just the request body
but the **HTTP transport layer
+ itself**: Gremlin Server must handle the HTTP/1.1 specification correctly,
so any request must be handled
+ safely however its request line, headers, chunked/streamed body, or
keep-alive connection sequence is
+ crafted, with no path to access or DoS the server. *Violation symptom:*
server crash / unbounded
+ allocation / deadlock from a malformed or pre-auth request, or a crafted
HTTP message or request sequence.
+ *Severity:* security-critical (remote DoS) if pre-auth.
+- **Request isolation.** One request's bindings and state must not leak into
or alter another's
+ (per-request bindings, thread-pool dispatch, §5). Transactions are the
deliberate stateful exception
+ (§11b). *Violation symptom:* cross-request state leakage or interference.
*Severity:*
+ security-critical.
+- **Parser integrity (`gremlin-language`).** A crafted Gremlin string cannot
break out of a string literal
+ to inject additional traversal steps. This is the safe string-to-traversal
path, distinct from building a
+ Groovy string by concatenation, which is the calling application's concern
(§9). The same holds for the
+ GQL string of a `match(String)` request, parsed server-side by the
`gql-gremlin` grammar. That grammar is
+ reference code active on the default distribution (TinkerGraph registers
it), so its robustness (no
+ crash/hang/OOM on malformed GQL) and integrity (no breakout into the
enclosing traversal) are in-model. A provider that does
+ not register a declarative-match strategy leaves the step non-executable
(§3). *Violation symptom:*
+ grammar breakout / step injection from a value that should stay a literal.
*Severity:* critical.
+
+- **Deserializer integrity.** The wire deserializer (GraphBinary), GraphSON
and **Gryo in its locked default
+ (`registrationRequired=true`)** reading attacker bytes do not lead to
arbitrary object instantiation / code
+ execution beyond the registered type set. Because `inject()` and value
arguments let a request carry any
+ supported type, a bug in a **registered** type's (de)serializer that
crashes/OOMs the reader is also
+ in-model, on **both** the server (request) and the GLV (response) side. The
GraphML reader disables
+ external entities and DTDs by default (XXE-safe). *Violation symptom:*
deserialization gadget / RCE / XXE,
+ or a registered-type serializer crashing/OOMing either end. *Severity:*
critical. Gryo is not on the wire,
+ and unlocked Gryo or a caller-supplied unhardened XML factory is
out-of-model (user responsibility, §9).
+- **Provider Defined Type (PDT) hydration.** Wire (de)serialization of the PDT
holder is a registered type
+ like any other (TinkerPop, above). Turning it into a typed object via a
`PDTRegistry` adapter is **opt-in,
+ off by default** (added by the operator server-side, the user client-side).
The registered types and their
+ constructor/`fromFields` side effects are **that party's** responsibility
(§3). The hydration **mechanism**
+ is TinkerPop's: it must stay **inert with no registry configured** (no
request triggers hydration when
+ nothing is registered) and, when configured, **instantiate only registered
types** (an unknown name stays
+ a data holder, not a gadget) without crash/OOM/hang. *Severity:* critical.
*(documented — `PDTRegistry`,
+ `@ProviderDefined`)*
+- **Resource bounds — split.** Malformed/pre-auth input that
crashes/OOMs/hangs the server is **in-model**
+ (above). Ordinary expensive traversals / large results are **operator
capacity**, NOT in-model, unless a
+ specific bug applies (super-linear amplification, a missing-where-expected
limit, an unbounded traversal).
+ A grammatically valid string the parser accepts must not itself enable DoS
from small input, e.g. ReDoS via
+ a pathological `regex` pattern, which is the in-model amplification case.
+- **Client (GLV) robustness against hostile server responses.** A GLV
deserializing response bytes from a
+ malicious/compromised server (or a MITM) does not crash/OOM/execute code.
*Violation symptom:* client
+ crash/OOM/RCE from crafted responses. *Severity:* critical.
+- **No pass-through string can harm the GLV.** Outbound request construction
is otherwise not a surface,
+ because its input is the trusted calling application. This property covers
only the pass-through case: an
+ application forwarding an untrusted end-user string verbatim (e.g.
`client.submit(userString)`) must not
+ cause code execution, a crash, a hang, or resource exhaustion **in the GLV
itself**. Its *server-side*
+ effect is Gremlin-injection, the application's responsibility (§9).
*Violation symptom:* a submitted
+ string that harms the GLV that submitted it. *Severity:* high.
+
+## §9 Security properties the project does *not* provide
+
+*(The highest-value section for integrators.)*
+
+- **Groovy script execution is arbitrary code execution by design, not a
sandbox.** The shipped default
+ `GremlinLangScriptEngine` evaluates only Gremlin and runs no arbitrary code.
When an operator instead
+ enables `gremlin-groovy`, that engine evaluates attacker-supplied code in
the server process. The docs
+ state scripts then have "access to the full power of their language and the
JVM." Submitting a Groovy
+ script that runs server-side code is **`BY-DESIGN`** for a principal the
deployment permits to script.
+ Enabling `gremlin-groovy` is a non-default operator choice. Restricting it
(allow-list, sandbox) or
+ keeping the default Groovy-free engine, and authenticating who may script,
is the operator's job. A scan
+ reporting "Gremlin Server allows arbitrary code execution via scripts" is
by-design unless it bypasses a
+ *configured* restriction.
+- **No transport confidentiality/integrity unless TLS is enabled.** TLS is off
in the shipped default (see
+ §5a). Until the operator enables it, the server does not defend against a
network attacker reading or
+ modifying client traffic. On the client side, a GLV sends its credentials
with the request, so without TLS
+ (or against a MITM) a driver can disclose those credentials to a hostile
endpoint. A driver configured
+ without TLS / certificate validation is a misconfiguration and is
out-of-scope. *(documented — TLS off by
+ default)*
+- **No authentication or authorization by default (assumed).** If the
shipped/default configuration runs
+ with auth off, an exposed server is reachable by anyone on the network. This
is an operator deployment
+ concern, not a code bug.
+- **No attribution/audit by default.** Audit logging is off by default (§5a),
so a default deployment keeps
+ no record of who ran which query. Enabling it (`enableAuditLog`) is the
operator's responsibility (§10).
+
+- **No built-in data-access control.** There is no element-level (CRUD)
authorization on graph data.
+ Access is bounded only by which traversal sources the operator exposes and
by a provider-supplied
+ `Authorizer` (which does not ship, §5a). A client within its grants can
read/write/delete any data the
+ exposed traversal source reaches.
+- **Gryo / Kryo deserializer integrity holds only under the locked default.**
Gryo defaults to a registration
+ allow-list (`registrationRequired=true`), so it is not an
arbitrary-instantiation sink, and a break within
+ that locked config is a `VALID` bug like any deserializer. **Running Gryo
unlocked
+ (`registrationRequired=false`) is not a safe boundary against untrusted
bytes and is the user's
+ responsibility.** (A few registered types use Java native serialization, a
gadget caveat even when locked.)
+ Gryo is not on the wire, so this is an IO/file-surface concern (`io()` step,
persistence, OLAP).
+
+- **A `TraversalStrategy` is not an access-control boundary on its own.** The
Gremlin language lets any
+ request remove or replace strategies on its traversal source
(`withoutStrategies()`,
+ `withStrategies()`), so a strategy applied by the operator only restricts a
client when an `Authorizer`
+ denies strategy removal/modification, as the reference documentation states.
Strategies also act at the
+ traversal layer, not the storage layer (§5a). *(documented — Gremlin grammar
`withoutStrategies`;
+ `gremlin-applications.asciidoc` "Authorization")*
+- **Ordinary resource exhaustion is not a defended property.** Expensive
traversals / large results that
+ consume CPU/memory are an operator capacity concern unless a specific bug
applies (§8).
+- **No defense against a malicious operator / host.**
+- **False friends:**
+ - "Authentication is available" does **not** mean it is **on**. It must be
configured (§5a).
+ - **A safe-language script is not a sandbox for the calling application's
own injection.** Injection/abuse
+ via a calling application that builds a Gremlin string by concatenating
its own untrusted input is the
+ calling application's responsibility. Note this is distinct from a
`gremlin-language` parser breakout,
+ which is an in-model TinkerPop bug (§8).
+ - "Gremlin is just a query language" is misleading. The **string** form can
run through a Groovy engine, so
+ it is code, not a constrained query.
+
+## §10 Downstream responsibilities (operator/deployer)
+
+- Do **not** deploy the shipped getting-started `gremlin-server.yaml` as-is.
Before exposing Gremlin Server
+ on a public/untrusted network, harden it: enable TLS and an authenticator,
and (given no authorizer ships)
+ supply an `Authorizer`, especially if scripting is enabled.
+- Enable authentication (`Authenticator`) and authorization (`Authorizer`) for
any non-trivial deployment.
+- **Restrict script execution:** prefer the default Groovy-free
`GremlinLangScriptEngine`, which evaluates
+ only Gremlin. If `gremlin-groovy` is needed, apply the "Protecting Script
Execution" controls (sandbox /
+ compilation customizers / allow-list) and restrict who may submit scripts.
+- Enable TLS (off by default) where traffic crosses an untrusted segment.
+- Scope `cors.allowedOrigins` to specific origins for browser-facing
deployments (defaults to `["*"]`).
+- Enable audit logging (`enableAuditLog`, off by default) where attribution of
requests is needed.
+- Use the wire serializers (GraphBinary recommended for drivers). Keep Gryo
locked
+ (`registrationRequired=true`), and do not read untrusted files through
**unlocked** Gryo.
+- Apply per-request resource limits (`evaluationTimeout`,
`maxRequestContentLength`, etc.) appropriate to capacity.
+- Set filesystem permissions so only the server user can read the config /
data directories.
+
+## §11 Known misuse patterns
+
+*(Draft one-liners, expand before publishing.)*
+
+- Exposing the shipped getting-started default (no TLS, no auth) on an
untrusted network instead of
+ hardening it first, especially with scripting enabled.
+- Treating the script-engine sandbox as a complete RCE boundary rather than
restricting who may script.
+- Building Gremlin by concatenating the calling application's untrusted input
into a Groovy string
+ (Gremlin-injection). This is distinct from a `gremlin-language` parser
breakout, which is in-model (§8).
+- Reading untrusted files through **unlocked** Gryo
(`registrationRequired=false`).
+
+## §11a Known non-findings (recurring false positives)
+
+*(Inferred unless tagged. The PMC's confirmations here are the
highest-leverage suppression input.)*
+
+- "Gremlin Server executes arbitrary code via scripts" — by-design when
scripting is enabled for the
+ principal (§9), and not a finding unless it bypasses a *configured*
restriction. Disposition:
+ `BY-DESIGN: property-disclaimed`.
+- "String lambdas enable code execution" — a string lambda is server-side code
like any script, so this is
+ by-design when a code-capable engine is configured (§9), and not a finding
unless it bypasses a
+ *configured* restriction. Disposition: `BY-DESIGN: property-disclaimed`.
+- "No authentication / no TLS by default" — operator deployment responsibility
(§9/§10), not a code bug in
+ itself. Disposition: `BY-DESIGN: property-disclaimed`.
+- "Gryo/Kryo deserialization can be exploited" — Gryo is not on the wire, so a
request-path report is
+ factually mistaken and needs no disposition (§13). Under the locked default
+ (`registrationRequired=true`) a real break is `VALID`, whereas exploiting
**unlocked** Gryo on
+ untrusted files is the user's responsibility (§9/§10). Disposition for the
unlocked-file variant:
+ `BY-DESIGN: property-disclaimed`.
+- "Expensive traversal consumes CPU/memory" — operator capacity concern,
unless a specific bug applies
+ (§8/§9). Disposition: `BY-DESIGN: property-disclaimed`.
+- "A configured `ReadOnlyStrategy` / `SubgraphStrategy` / `PartitionStrategy`
was bypassed" — whether by
+ removing the strategy via `withoutStrategies()` or by stepping around it
(direct `Vertex.property()`,
+ `mergeV`/`mergeE`), a strategy is not an access-control boundary on its own
(§9). A finding only exists
+ where a configured `Authorizer` pins the strategy and the pin is evaded
(§8). Disposition:
+ `BY-DESIGN: property-disclaimed`.
+- "Calling application concatenates untrusted input into a Groovy string
(Gremlin-injection)" — the calling
+ application's responsibility (§9). A `gremlin-language` parser breakout is
the opposite: an in-model
+ TinkerPop bug (§8). Disposition: `BY-DESIGN: property-disclaimed`.
+- Findings in any test-only module, any module containing examples, or build
tooling (e.g. `gremlin-test`,
+ `gremlin-examples`, `gremlin-tools`) — out of scope (§3). Disposition:
+ `OUT-OF-MODEL: unsupported-component`.
+
+## §11b Known problems
+
+*(Acknowledged, accepted weaknesses of Gremlin Server as it works today.)*
+
+- **Transactions can be shared.** A transaction is identified by a
server-generated UUID and looked up with
+ **no owning-user check**, so any client presenting a valid id accesses that
transaction's state. The default
+ server provides no per-user isolation, and this is accepted as how Gremlin
Server works. A deployment
+ needing isolation must use a provider that adds it.
+
+## §12 Conditions that would change this model
+
+- A change to the default auth / TLS / scripting posture (e.g.
auth-on-by-default, scripts-off-by-default).
+- A new client-reachable surface or protocol on Gremlin Server.
+- A change to the default-enabled wire serializer set, or the reintroduction
of Gryo (or any Kryo-based
+ format) as a wire serializer.
+- Promoting a test-only / example module into a production trust surface.
+- A change to the OLAP (Hadoop/Spark) trust posture.
+- A report that cannot be routed to a single §13 disposition (→ revise the
model).
+
+## §13 Triage dispositions
+
+A disposition is the answer a security report receives after triage: a
TinkerPop bug that needs a fix,
+some other party's responsibility, or known and accepted behavior. A report
may contain more than one
+finding, and each finding gets **exactly one** disposition from the table
below. The rows do not
+overlap. A finding that seems to match two rows, or none, means the table
itself has a defect and takes
+`MODEL-GAP` so that the model gets fixed (§12). A report claiming something
the code simply does not do
+(for example, Gryo reachable over the network) is answered by correcting the
facts and needs no
+disposition at all.
+
+A finding is classified by **what the attack needs in order to work**, not by
the setup it happened to
+be demonstrated on. For example, a crash bug shown against a server running
the insecure
+getting-started configuration does not need that configuration. The same crash
works, without
+credentials, against a hardened server too, so it is `VALID`. The insecure
default decides the outcome
+only when the finding is, in substance, "this particular server was left
unhardened."
+
+The lists in §11a and §11b exist to save repeated work: each entry is a
finding that keeps coming back,
+recorded together with the disposition it takes. They are worked examples of
this table, not extra
+rules on top of it.
+
+| Disposition | Meaning | Based on |
+| --- | --- | --- |
+| `VALID` | A real TinkerPop bug: it breaks one of the §8 security properties
through an attacker or input the model covers. Examples: bypassing
authentication/authorization or slipping past a configured restriction,
crashing or hanging the server with malformed or unauthenticated input, a
deserializer executing code it should not, or the parser mishandling crafted
input or letting a value escape its string literal. | §8, §6, §7 |
+| `VALID-HARDENING` | Not a vulnerability, but still useful: no §8 property is
broken, and the report points at a practical change that would make one of the
§11 misuse patterns harder to fall into. Example: "no authentication by
default" is by design, but a startup warning when `AllowAllAuthenticator` is
active would be a sensible outcome of that report and takes this disposition.
Tracked as an ordinary improvement. | §11 |
+| `OUT-OF-MODEL: trusted-input` | The attack only works for someone who
already has the operator's own access: the host, the server process,
`gremlin-server.yaml`, or the data directory. This includes a malicious
operator (§9). Someone with that access can already do anything the operator
can, so the attack gains nothing new. | §6, §7 |
+| `OUT-OF-MODEL: adversary-not-in-scope` | The attack needs an attacker the
model deliberately leaves out (side channels/timing), or the whole finding is
that one specific deployment was left on the insecure getting-started default,
which is that operator's mistake to fix. A complaint about the shipped default
itself is `BY-DESIGN`. A real code bug that was merely demonstrated on an
unhardened server is judged on its own needs, usually `VALID`. | §3, §7 |
+| `OUT-OF-MODEL: unsupported-component` | The buggy code is not TinkerPop's
(§3 triage test): it is in a test-only or example module, in build tooling, or
in a provider's own code or their modifications to the reference code
(including a remote graph provider that shares no TinkerPop code). Sent to the
provider. | §3 |
+| `OUT-OF-MODEL: non-default-build` | A genuine bug, but one that only exists
when the operator turns on a discouraged, non-default §5a setting, for example
a robustness bug inside the optional `gremlin-groovy` engine. Different from
`BY-DESIGN`: behavior §9 already disclaims, such as Groovy scripts running
code, is not a bug at all and takes that row instead. | §5a |
+| `BY-DESIGN: property-disclaimed` | The behavior is exactly what §9 says
TinkerPop does not defend against: scripts executing code within what the
deployment allows, the shipped no-TLS/no-auth default, ordinary resource
exhaustion from expensive queries, reading untrusted files through unlocked
Gryo, or an application building queries out of its own users' raw input. The
software works as documented. When the scenario needs the operator's own
access, `trusted-input` applies instead. | §9 |
+| `KNOWN-PROBLEM` | Matches the acknowledged weakness in §11b (transaction
sharing), which the §8 enforcement property explicitly excepts. Already known
and accepted, not a new finding. A deployment that needs the missing protection
must use a provider that adds it. | §11b |
+| `MODEL-GAP` | Fits no row, or more than one. That is a defect in the model
itself, and §12 requires revising it. | §12 |
