STG Security Advisory: [SSA-20041215-18] Vulnerability of uploading files with multiple extensions in phpBB Attachment Mod
STG Security Advisory: [SSA-20041215-18] Vulnerability of uploading files
with multiple extensions in phpBB Attachment Mod
Revision 1.1
Date Published: 2004-12-15 (KST)
Last Update: 2004-12-15
Disclosed by SSR Team (advisory@xxxxxxxxxxxxxxx)
Summary
========
phpBB Attachment Mod is file upload module for phpBB. However, an input
validation flaw can cause malicious attackers to run arbitrary commands with
the privilege of the HTTPD process, which is typically run as the nobody
user.
Vulnerability Class
===================
Implementation Error: Input validation flaw
Impact
======
High : arbitrary command execution.
Affected Products
================
Attachment Mod 2.3.10 and prior.
Vendor Status: FIXED
====================
2004-12-08 Vulnerability found.
2004-12-08 Attachment Mod developer notified.
2004-12-13 Update version released.
2004-12-15 Official release.
Details
=======
Attachment Mod doesn't implemented to check multiple extensions of uploaded
files, e.g. attack.php.rar, so malicious attackers can upload arbitrary
script files (php, pl, cgi, etc) to a web server. This is originated from a
feature of Apache MIME module (mod_mime), which regards attack.php.rar as a
normal PHP file and execute the file through mod_php module with the
privilege of the HTTPD process.
cf. http://httpd.apache.org/docs/mod/mod_mime.html - "Files with Multiple
Extensions" : it's a feature, not a bug.
Solution
=========
Update to 2.3.11
http://www.opentools.de/board/viewtopic.php?t=3590
Vendor URL
==========
http://www.opentools.de/
Credits
======
Jeremy Bae at STG Security