XChat: malformed dcc send request denial of service

1.  Gentoo Linux Security Advisory

Version Information

Related bugreports: #35623

Synopsis

A bug in XChat could allow malformed dcc send requests to cause a denial of service.

2.  Impact Information

Background

XChat is a multiplatform IRC client.

Description

There is a remotely exploitable bug in XChat 2.0.6 that could lead to a denial of service attack. Gentoo wishes to thank lloydbates for discovering this bug, as well as jcdutton and rac for submitting patches to fix the bug.

Impact

A malformed DCC packet sent by a remote attacker can cause XChat to crash.

3.  Resolution Information

Workaround

There is no known workaround at this time.

Resolution

For Gentoo users, xchat-2.0.6 was marked ~arch (unstable) for most architectures. Since it was never marked as stable in the portage tree, only xchat users who have explictly added the unstable keyword to ACCEPT_KEYWORDS are affected. Users may updated affected machines to the patched version of xchat using the following commands:

# emerge sync
# emerge -pv '>=net-irc/xchat-2.0.6-r1'
# emerge '>=net-irc/xchat-2.0.6-r1'
# emerge clean

This assumes that users are running with ACCEPT_KEYWORDS enabled for their architecture.

4.  References

• XChat Announcement