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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 <h...@apache.org> 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 <h...@apache.org> Date: 2017-02-14T22:41:01Z Update Admin Doc source for 4lw changes. commit b808940d5aed3c707b50df417a558123df4a03cd Author: Michael Han <h...@apache.org> Date: 2017-02-15T00:02:35Z Update doc with security guideline. commit f296225793dcf7bc289b63b2ff9ca7d30291fb69 Author: Michael Han <h...@apache.org> 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)