Centaura Technologies Security Research Lab Advisory

Product Name: vpopmail-CGIApps
Systems: Linux/OpenBSD/FreeBSD/NetBSD
Severity: High Risk
Remote: Yes
Category: Insuficient input checking
Vendor URL: http://diario.buscadoc.org/index.php?topic=3DProgramas
Advisory Author: Ignacio Vazquez
Advisory URL: http://www.centaura.com.ar/infosec/adv/vpopmailCGIappsdomai=
n.txt
Date: 14 October 2002
Advisory Code: CTADVIIC044


=2E:Introduction

vpopmail-CGIApps is a qmail-vpopmail domain administrator
written in Python.

=2E: Impact
An attacker can execute arbitrary code as the setuid user of the
script (normally vpopmail), giving him the posibility to add/modify
and delete accounts/domains from the database, add and edit system
files, etc.
This can lead to complete e-mail server compromise.

=2E: Description
By providing a special crafted data in the domain form field
(typing ; in there), the script executes os.system() function,
adds the domains and then executes the command after the ;

=2E: Exploit.

In "domini" field, put: "; echo 'test' > /tmp/vpoptest"
When you send the form, a new file in /tmp will be created.

=2E: Workaround

Before the os.system() method is called:

string.replace(domini, ";", "")
string.replace(passx, ";", "")
os.system('/usr/bin/sudo -u root /home/vpopmail/bin/vpasswd' +" "+ direc =
+ "=20
"+ passx)

=2E: Official Fix Information

The vendor has released version 0.3 in response of this advisory

-----

Ignacio Vazquez
<ivazquez@centaura.com.ar>

Director of Technology
Security Labs Manager

Centaura Technologies
http://www.centaura.com.ar