[
https://issues.apache.org/jira/browse/ZOOKEEPER-2693?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15867008#comment-15867008
]
ASF GitHub Bot commented on ZOOKEEPER-2693:
-------------------------------------------
GitHub user hanm opened a pull request:
https://github.com/apache/zookeeper/pull/179
ZOOKEEPER-2693: DOS attack on wchp/wchc four letter words (4lw)
This is for master / branch-3.5:
* Introduce a new configuration option that by default turn off 4lw.
* Update docs that explicitly states ZooKeeper should not be deployed open
to world for access and deprecating 4lw in favor of Jetty.
With these combined, the attack described in ZOOKEEPER-2693 is not possible
if ZooKeeper is put behind a firewall where Jetty AdminServer is not publicly
accessible.
Note for tests: I did not add any unit tests to test 4lw disabling because
it is fairly obvious (though I have to update a place to prevent existing test
broken, because we are using 4lw extensively to query test server states. We
could query AdminServer instead but I consider that's a future work item - and
even if we use AdminServer exclusively we can't dump 4lw completely because
AdminServer test depends on 4lw - chicken egg problem.).
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/hanm/zookeeper ZOOKEEPER-2693
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/zookeeper/pull/179.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #179
----
commit b70e19ecdcd8f78bb8ac2d380a07968cbb683b3b
Author: Michael Han <[email protected]>
Date: 2017-02-14T22:24:05Z
Initial commit that turns four letter words off by default for 3.5.x branch.
Pending test cases and doc changes.
commit 7f3420573774a23dafc8fcbbe3873392d0c9090a
Author: Michael Han <[email protected]>
Date: 2017-02-14T22:41:01Z
Update Admin Doc source for 4lw changes.
commit b808940d5aed3c707b50df417a558123df4a03cd
Author: Michael Han <[email protected]>
Date: 2017-02-15T00:02:35Z
Update doc with security guideline.
commit f296225793dcf7bc289b63b2ff9ca7d30291fb69
Author: Michael Han <[email protected]>
Date: 2017-02-15T00:06:07Z
Fix broken tests.
----
> DOS attack on wchp/wchc four letter words (4lw)
> -----------------------------------------------
>
> Key: ZOOKEEPER-2693
> URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2693
> Project: ZooKeeper
> Issue Type: Bug
> Components: security, server
> Affects Versions: 3.4.0, 3.5.1, 3.5.2
> Reporter: Patrick Hunt
> Priority: Blocker
> Fix For: 3.4.10, 3.5.3
>
>
> The wchp/wchc four letter words can be exploited in a DOS attack on the ZK
> client port - typically 2181. The following POC attack was recently published
> on the web:
> https://webcache.googleusercontent.com/search?q=cache:_CNGIz10PRYJ:https://www.exploit-db.com/exploits/41277/+&cd=14&hl=en&ct=clnk&gl=us
> The most straightforward way to block this attack is to not allow access to
> the client port to non-trusted clients - i.e. firewall the ZooKeeper service
> and only allow access to trusted applications using it for coordination.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
