Majordomo2 Directory Traversal

`______________________________________________________________________  
-------------------------- NSOADV-2011-003 ---------------------------  
  
Majordomo2 'help' Command Directory Traversal (Patch Bypass)  
______________________________________________________________________  
______________________________________________________________________  
  
111101111  
11111 00110 00110001111  
111111 01 01 1 11111011111111  
11111 0 11 01 0 11 1 1 111011001  
11111111101 1 11 0110111 1 1111101111  
1001 0 1 10 11 0 10 11 1111111 1 111 111001  
111111111 0 10 1111 0 11 11 111111111 1 1101 10  
00111 0 0 11 00 0 1110 1 1011111111111 1111111 11 100  
10111111 0 01 0 1 1 111110 11 1111111111111 11110000011  
0111111110 0110 1110 1 0 11101111111111111011 11100 00  
01111 0 10 1110 1 011111 1 111111111111111111111101 01  
01110 0 10 111110 110 0 11101111111111111111101111101  
111111 11 0 1111 0 1 1 1 1 111111111111111111111101 111  
111110110 10 0111110 1 0 0 1111111111111111111111111 110  
111 11111 1 1 111 1 10011 101111111111011111111 0 1100  
111 10 110 101011110010 11111111111111111111111 11 0011100  
11 10 001100 0001 111111111111111111 10 11 11110  
11110 00100 00001 10 1 1111 101010001 11111111  
11101 0 1011 10000 00100 11100 00001101 0  
0110 111011011 0110 10001 101 11110  
1011 1 10 101 000001 01 00  
1010 1 11001 1 1 101 10  
110101011 0 101 11110  
110000011  
111  
______________________________________________________________________  
______________________________________________________________________  
  
Title: Majordomo2 'help' Command Directory Traversal  
Severity: Medium  
Advisory ID: NSOADV-2011-003  
CVE: CVE-2011-0063  
Found Date: 03.02.2011  
Date Reported: 03.02.2011  
Release Date: 19.02.2011  
Author: Nikolas Sotiriu  
Mail: nso-research at sotiriu.de  
Website: http://sotiriu.de/  
Twitter: http://twitter.com/nsoresearch  
Advisory-URL: http://sotiriu.de/adv/NSOADV-2011-003.txt  
Vendor/Project: http://www.mj2.org/  
Affected Products: majordomo2 <= 20110203  
Remote Exploitable: Yes  
Local Exploitable: No  
Patch Status: Vendor released a patch (See Solution)  
Discovered by: Nikolas Sotiriu  
Disclosure Policy: http://sotiriu.de/policy.html  
Thanks to: Thierry Zoller: For the permission to use his  
Policy  
  
  
  
Background:  
===========  
  
Majordomo 2 is an upwardly-compatible rewrite of the popular majordomo  
mailing list manager software by Jason Tibbitts and Michael Yount.  
  
  
  
Description:  
============  
  
Majordomo2 <= 20110203 is affected by a Directory Traversal  
vulnerability due to parameter 'extra' of the 'help' command in the  
function '_list_file_get()' is not properly sanitized.  
  
The original bug was made public on 03.02.2011 by Michael Brooks  
of sitewat.ch:  
  
https://sitewat.ch/en/Advisory/View/1  
https://bugzilla.mozilla.org/show_bug.cgi?id=628064  
  
I discovered, that the patch, which is in the CVS since version 20110125  
don't protect against the Directory Traversal bug.  
  
https://bug628064.bugzilla.mozilla.org/attachment.cgi?id=506481  
  
The diff build in the regex '$file =~ s!/?\.\./?!!g;', which deletes  
'../' from $file. Bypassing this regex is quiet simple by using './.../'  
insted '../'.  
  
  
  
Proof of Concept :  
==================  
  
HTTP:  
http://<target>/cgi-bin/mj_wwwusr?passw=&list=GLOBAL&user=&func=help&  
extra=./..././..././..././..././..././..././..././.../etc/passwd  
  
SMTP:  
help ./..././..././..././..././..././..././..././.../etc/passwd  
  
  
  
Solution:  
=========  
  
Update to Majordomo2 >= 20110204  
  
http://ftp.mj2.org/pub/mj2/snapshots/2011-02/majordomo-20110204.tar.gz  
  
  
  
References:  
===========  
  
Sitewatch Advisory: https://sitewat.ch/en/Advisory/View/1  
Original Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=628064  
Patch Bypass: https://bugzilla.mozilla.org/show_bug.cgi?id=631307  
  
  
  
Disclosure Timeline (YYYY/MM/DD):  
=================================  
  
2011.02.03: Patch bypass vulnerability found  
2011.02.03: Informed security [at] mozilla.org  
2011.02.03: Mozilla opend Bug 631307 in bugzilla  
2011.02.03: Jason Tibbitts comitted a fix (Sorry again)  
2011.02.04: Snapshot available for download  
2011.02.04: Discuss the public disclosure  
2011.03.04: Got the Bug Bounty Money  
2011.03.08: Release of Advisory  
  
  
  
  
  
  
`