[33228] in bugtraq
[SST]ServU MDTM command remote buffero verflow adv
daemon@ATHENA.MIT.EDU (icbm)
Sat Jan 24 13:50:26 2004
Message-ID: <20040124072206.3460.qmail@mail.securityfocus.com>
Date: Sat, 24 Jan 2004 15:49:24 +0800
From: "icbm" <icbm@0x557.net>
To: "bugtraq" <bugtraq@securityfocus.com>,
"full-disclosure" <full-disclosure@lists.netsys.com>
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Serv-U Ftp Server Long Filename Stack Overflow Vunlnerablity
Application: Serv-U
Affected Versions: All versions prior 4.2 (include 4.1.0.11)
Vendor: RhinoSoft (http://www.rhinosoft.com
http://www.serv-u.com)
URL: http://www.0x557.org/release/servu.txt
Vunlnerablity:
An internal memory buffer may be overrun while handling "site chmod" command
with a filename containg excessive data. This condition may be exploited by
attackers to ultimately execute instructions with the priviledges of the serv-u
process, typically administator or system.
Details:
While exectuing chmod on a nonexistent file, serv-u will call sprintf to
construct response string. And the code is like
sprintf(dst, "%s: No such file or directory.", filename);
The length of dst buffer is only 256 bytes.If a long filename was sent,
serv-u will crash.
A writable directory is needed to exploit this vulerablity.By overwriting SEH,
we have created proof-of-concept exploit successfully on win2k/xp.
Solution:
Upgrade to servu 5.0.
Credits:
kkqq <kkqq@0x557.org> has indenpendently discovered this vulerablity.
All members of SST (http://www.0x557.org).
lgx and eyas.
Rob Beckers for indentifing and fixing this vulerablity.
About SST:
Do we really exist?
icbm
icbm@0x557.net
2004-01-24
