Hi,
HAProxy 2.6.15 was released on 2023/08/09. It added 73 new commits
after version 2.6.14.
As mentioned in the 2.8.2 announce, some moderate security issues were
addressed.
The high severity issues addressed in this version are the following:
- performing multiple large-header replacements at once can sometimes
overwrite parts of the contents of the headers if header size is
increased. This may happen with the "replace-header" action, when the
buffer gets too fragmented, a temporary one is needed to realign it,
then they are permutted. But if this happens more than once, the
allocated temporary buffer could be the one that had just been used,
where live data will be overwritten but the new ones. This can cause
garbage to appear in headers, and might possibly trigger some asserts
depending on the damage and where this passes. This issue was reported
by Christian Ruppert.
- the H3 decoder used to properly reject malformed header names, but
forgot to do so for header values, as was already done for H2. This
could theoretically be used to attack servers behind, though for this
to happen, one would need to have a QUIC listener and a tool permitting
to send such malformed bytes (not granted).
- the check for invalid characters on content-length header values doesn't
reject empty headers, which can pass through. And since they don't have
a value, they're not merged with next ones, so it is possible to pass
a request that has both an empty content-length and a populated one.
Such requests are invalid and the vast majority of servers will reject
them. But there are certainly still a few non-compliant servers that
will only look at one of them, considering the empty value equals zero
and be fooled with this. Thus the problem is not as much for mainstream
users as for those who develop their own HTTP stack or who purposely use
haproxy to protect a known-vulnerable server, because these ones may be
at risk. This issue was reported by Ben Kallus of Dartmouth College and
Narf Industries. A CVE was filed for this one. There is a work-around,
though: simply rejecting requests containing an empty content-length
header will do the job:
http-request deny if { hdr_len(content-length) 0 }
Then there are a bunch of lower severity ones, particularly:
- the URL fragments (the part that follows '#') are not allowed to be
sent on the wire, and their handling on the server side has long been
ambiguous. Historically most servers would trim them, nowadays with
stronger specification requirements most of them tend to simply reject
the request as invalid. Till now we did neither of these, so they
could appear at the end of the "path" sample fetch contents. It can be
problematic in case path_end is used to route requests. For example,
a rule doing routing "{ path_end .png .jpg }" to a static server could
very well match "index.html#.png". The question of how best to proceed
in this case was asked to other HTTP implementers and the consensus was
clearly that this should be actively rejected, which is even specifically
mandated in certain side-protocol specs. A measurement on haproxy.org
shows that such requests appear at a rate of roughly 1 per million, and
are either emitted by poorly written crawlers that copy-paste blocks of
text, or are sent by vulnerability scanners. Thus a check was added for
this corner case which is now blocked by default. In case anyone would
discover that they're hosting a bogus application relying on this, this
can be reverted using "option accept-invalid-http-request". This issue
was reported by Seth Manesse and Paul Plasil.
- in H3, the FIN bit could be handled before the last frame was processed,
triggering an internal error.
- H3: the presence of a content-length header was not reported internally,
causing the FCGI mux on the backend to stall during uploads from QUIC to
FCGI.
- listener: the proxy's lock is needed in relax_listener(), otherwise we
risk a deadlock through an ABBA pattern that could happen when a listener
gets desaturated.
- logging too large messages to a ring can cause their loss, due to the
maxlen parameter not being accurately calculated.
- quic: a few issues affect the retry tokens (used when a listener is
under flood): a check was missing on the dcid, which could probably
be used to try to create more than one connection per token; the
internal tick was used for the timestamp used in tokens instead of
the wall-clock time, causing a risk that a token will fail to
validate against another node from the same cluster; finally the
initial vector used for random token generation was not strong
enough. Missing parenthesis in the PTO calculation formula could
possibly result in obscure bugs such as a connection probing
infinitely.
- quic: assorted minor-level issues that had already been addressed in
2.8.1.
- incomplete log server definitions were added to the global list of
servers, but freed without be delete from the list, which can cause
all sorts of issues and crashes when walking over that list or at
deinit() time.
- cache: s-maxage couldn't override "max-age=0" as it ought to, according
to the standard.
- the "namespace" keyword in default-servers was parsed but ignored
- the duplicate stick-table name check did not work for tables declared
inside peers sections.
- mworker: automatically adjust the master's maxconn to support the
sockets used to connect to workers.
- http compression will now flush partial messages to allow low-latency
interactive communications to work (e.g. CouchDB's heartbeats).
- h2: control frames such as PING could refresh the idle timer, preventing
the keep-alive timeout from doing its job (already fixed in 2.8.0 and
2.7.9).
The rest is of much lower importance or probability, and the usual DOC, CI
and cleanup stuff. Older versions will follow, reusing this changelog when
it fits.
Thanks to all those who reported issues, tested fixes and helped with the
backports!
Please find the usual URLs below :
Site index : https://www.haproxy.org/
Documentation : https://docs.haproxy.org/
Wiki : https://github.com/haproxy/wiki/wiki
Discourse : https://discourse.haproxy.org/
Slack channel : https://slack.haproxy.org/
Issue tracker : https://github.com/haproxy/haproxy/issues
Sources : https://www.haproxy.org/download/2.6/src/
Git repository : https://git.haproxy.org/git/haproxy-2.6.git/
Git Web browsing : https://git.haproxy.org/?p=haproxy-2.6.git
Changelog : https://www.haproxy.org/download/2.6/src/CHANGELOG
Dataplane API :
https://github.com/haproxytech/dataplaneapi/releases/latest
Pending bugs : https://www.haproxy.org/l/pending-bugs
Reviewed bugs : https://www.haproxy.org/l/reviewed-bugs
Code reports : https://www.haproxy.org/l/code-reports
Latest builds : https://www.haproxy.org/l/dev-packages
Willy
---
Complete changelog :
Aurelien DARRAGON (17):
BUG/MINOR: server: inherit from netns in srv_settings_cpy()
BUG/MINOR: namespace: missing free in netns_sig_stop()
BUG/MINOR: tcp_sample: bc_{dst,src} return IP not INT
BUG/MEDIUM: sink: invalid server list in sink_new_from_logsrv()
BUG/MINOR: sink: missing sft free in sink_deinit()
BUG/MINOR: ring: size warning incorrectly reported as fatal error
BUG/MINOR: ring: maxlen warning reported as alert
BUG/MINOR: log: LF upsets maxlen for UDP targets
MINOR: sink/api: pass explicit maxlen parameter to sink_write()
BUG/MEDIUM: log: improper use of logsrv->maxlen for buffer targets
BUG/MINOR: log: fix missing name error message in cfg_parse_log_forward()
BUG/MINOR: log: fix multiple error paths in cfg_parse_log_forward()
BUG/MINOR: log: free errmsg on error in cfg_parse_log_forward()
BUG/MINOR: sink: invalid sft free in sink_deinit()
BUG/MINOR: sink: fix errors handling in cfg_post_parse_ring()
BUG/MINOR: sink/log: properly deinit srv in sink_new_from_logsrv()
BUG/MINOR: hlua: hlua_yieldk ctx argument should support pointers
Christopher Faulet (9):
REGTESTS: h1_host_normalization : Add a barrier to not mix up log messages
DOC: config: Fix fc_src description to state the source address is
returned
BUG/MINOR: sample: Fix wrong overflow detection in add/sub conveters
BUG/MINOR: http: Return the right reason for 302
BUG/MINOR: h1-htx: Return the right reason for 302 FCGI responses
BUG/MEDIUM: listener: Acquire proxy's lock in relax_listener() if
necessary
BUG/MEDIUM: h3: Properly report a C-L header was found to the HTX
start-line
BUG/MEDIUM: h3: Be sure to handle fin bit on the last DATA frame
BUG/MAJOR: http-ana: Get a fresh trash buffer for each header value
replacement
Dragan Dosen (1):
BUG/MINOR: chunk: fix chunk_appendf() to not write a zero if buffer is
full
Emeric Brun (6):
BUG/MEDIUM: quic: error checking buffer large enought to receive the
retry tag
BUG/MEDIUM: quic: token IV was not computed using a strong secret
BUG/MINOR: quic: retry token remove one useless intermediate expand
BUG/MEDIUM: quic: missing check of dcid for init pkt including a token
BUG/MEDIUM: quic: timestamp shared in token was using internal time clock
BUILD: quic: fix warning during compilation using gcc-6.5
Frédéric Lécaille (13):
BUG/MINOR: quic: Wrong encryption level flags checking
BUG/MINOR: quic: Missing initialization (packet number space probing)
BUG/MINOR: quic: ticks comparison without ticks API use
BUG/MINOR: quic: Missing random bits in Retry packet header
BUG/MINOR: quic: Wrong Retry paquet version field endianess
BUG/MINOR: quic: Wrong endianess for version field in Retry token
MINOR: quic: Move QUIC encryption level structure definition
MINOR: quic: Move packet number space related functions
MINOR: quic: Reduce the maximum length of TLS secrets
CLEANUP: quic: Remove server specific about Initial packet number space
BUG/MINOR: quic: Missing parentheses around PTO probe variable.
MINOR: quic: Make ->set_encryption_secrets() be callable two times
MINOR: quic: Useless call to SSL_CTX_set_quic_method()
Ilya Shipitsin (1):
CI: explicitely highlight VTest result section if there's something
Patrick Hemmer (1):
BUG/MINOR: config: fix stick table duplicate name check
Remi Tricot-Le Breton (1):
BUG/MINOR: cache: A 'max-age=0' cache-control directive can be overriden
by a s-maxage
Thierry Fournier (1):
BUG/MINOR: config: Remove final '\n' in error messages
Tim Duesterhus (1):
DOC: Add tune.h2.max-frame-size option to table of contents
William Lallemand (3):
BUG/MEDIUM: mworker: increase maxsock with each new worker
BUG/MINOR: mworker: leak of a socketpair during startup failure
DOC: configuration: describe Td in Timing events
Willy Tarreau (18):
BUG/MEDIUM: mux-h2: make sure control frames do not refresh the idle
timeout
BUG/MINOR: mux-h2: refresh the idle_timer when the mux is empty
IMPORT: slz: implement a synchronous flush() operation
MINOR: compression/slz: add support for a pure flush of pending bytes
BUILD: debug: avoid a build warning related to epoll_wait() in debug code
REORG: http: move has_forbidden_char() from h2.c to http.h
BUG/MAJOR: h3: reject header values containing invalid chars
BUG/MAJOR: http: reject any empty content-length header value
MINOR: ist: add new function ist_find_range() to find a character range
MINOR: http: add new function http_path_has_forbidden_char()
MINOR: h2: pass accept-invalid-http-request down the request parser
REGTESTS: http-rules: add accept-invalid-http-request for normalize-uri
tests
BUG/MINOR: h1: do not accept '#' as part of the URI component
BUG/MINOR: h2: reject more chars from the :path pseudo header
BUG/MINOR: h3: reject more chars from the :path pseudo header
REGTESTS: http-rules: verify that we block '#' by default for
normalize-uri
DOC: clarify the handling of URL fragments in requests
BUG/MINOR: http: skip leading zeroes in content-length values
firexinghe (1):
BUG/MINOR: hlua: add check for lua_newstate
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