ChatZilla <=v0.8.23 remote DoS vulnerability

[d4rkgr3y <grey_1999 () mail ru>]

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

---------------------------------
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@localhost 0dd]# gcc -o m00-ChatZilla m00-ChatZilla.c
[root@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@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@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 () securitylab ru]

Attachment: m00-ChatZilla.c
Description: