Subject: [yellowdog-updates] Yellow Dog Linux Security Update: YDU-20020127-2
dburcaw@newhope.terraplex.com
Date: Sun Jan 27 2002 - 18:08:13 MST
Yellow Dog Linux Security Announcement
--------------------------------------
Package: xchat
Issue Date: January 27, 2002
Priority: medium
Advisory ID: YDU-20020127-2
1. Topic:
Versions of xchat prior to version 1.8.7 contain a vulnerability
which allows an attacker to cause a vulnerable client to execute
arbitrary IRC server commands as if the vulnerable user had typed
them.
This security erratum updates xchat to version 1.8.7, which is
not vulnerable to this attack
2. Problem:
xchat is a popular IRC client. Recently xchat has been
found to contain a bug in the CTCP PING handling code which can
be exploited to execute IRC commands on the IRC server as the
vulnerable user. This can be used for example by an attacker
to /op or /deop, to /kick someone out of a channel, to force the
vulnerable user out of the channel with a /part, to change
channel modes via the /mode command, or to impersonate a user
via private /msg commands.
This bug does not appear to allow an attacker to execute commands
on the vulnerable computer, just to force IRC server commands to
be run as if the vulnerable user had typed them.
All previous versions of xchat are vulnerable, however only the 1.4.*
versions are vulnerable by default. With later versions (1.6.*, 1.8.*),
xchat is not vulnerable unless the user has enabled the client side
"percascii" variable with the command "/set percascii 1"
(from Red Hat advisory)
3. Solution:
a) Updating via yup...
We suggest that you use the Yellow Dog Update Program (yup)
to keep your system up-to-date. The following command(s) will
automatically retrieve and install the fixed version of
this update onto your system:
yup update xchat
b) Updating manually...
The update can also be retrieved manually from our ftp site
below along with the rpm command that should be used to install
the update. (Please use a mirror site)
ftp://ftp.yellowdoglinux.com/pub/yellowdog/updates/yellowdog-2.1/ppc/
rpm -Fvh xchat-1.8.7-1.72.0.ppc.rpm
4. Verification
MD5 checksum Package
-------------------------------- ----------------------------
75a3959a60589c2b06464a4afdc84150 ppc/xchat-1.8.7-1.72.0.ppc.rpm
7c31379536c3a9a1a7dc96eea6939f8f SRPMS/xchat-1.8.7-1.72.0.src.rpm
If you wish to verify that each package has not been corrupted or tampered with,
examine the md5sum with the following command: rpm --checksig --nogpg filename
5. Misc.
Terra Soft has setup a moderated mailing list where these security, bugfix, and package
enhancement announcements will be posted. See http://lists.yellowdoglinux.com/ for more
information.
For information regarding the usage of yup, the Yellow Dog Update Program, see
http://http://www.yellowdoglinux.com/support/solutions/ydl_general/yup.shtml
This archive was generated by hypermail 2a24 : Sun Jan 27 2002 - 19:24:16 MST