Poor BSDI squid permissions
Description: | on BSDI squid configuration files are owned by "www", which is the same UID that user CGI runs at. Thus a user could change start-squid to start a root shell, for example. |
Author: | "Jonathan A. Zdziarski" <jonz@NETRAIL.NET> |
Compromise: | user WWW privs -> root |
Vulnerable Systems: | BSDI 3.1 , perhaps other squid installs |
Date: | 7 May 1998 |
Date: Thu, 7 May 1998 15:49:07 -0400
From: "Jonathan A. Zdziarski" <jonz@NETRAIL.NET>
To: BUGTRAQ@NETSPACE.ORG
Subject: BSDI 3.1/Squid Default Owner
I noticed that by default, SQUID is installed on BSDi 3.1 with the
following permissions:
ls > ls -la
total 234
drwxrwxr-x 2 www www 512 Feb 7 1997 .
drwxrwxr-x 3 www www 512 Feb 7 1997 ..
-rwxr-xr-x 1 www www 3635 Jan 20 1997 access-extract-urls.pl
-rwxr-xr-x 1 www www 4269 Jan 20 1997 access-extract.pl
-rwxr-xr-x 1 www www 9168 Jan 20 1997 access-summary.pl
-rwxr-xr-x 1 www www 4153 Jan 20 1997 cache-summary.pl
-rwxr-xr-x 1 www www 20480 Jan 20 1997 cachemgr.cgi
-rwxr-xr-x 1 www www 4280 Jan 20 1997 client
-rwxr-xr-x 1 www www 4448 Jan 20 1997 dnsserver
-rwxr-xr-x 1 www www 36864 Jan 20 1997 ftpget
-rwxr-xr-x 1 www www 2388 Jan 20 1997 pinger
-rwxr-xr-x 1 www www 10235 Jan 20 1997 squid-logs.pl
-rwxr-xr-x 1 www www 980 Jan 20 1997 squid.daily
-rwxr-xr-x 1 www www 980 Jan 20 1997 squid.daily.sample
-rwxr-xr-x 1 www www 1813 Jan 20 1997 squid.weekly
-rwxr-xr-x 1 www www 1813 Jan 20 1997 squid.weekly.sample
-rwxr-xr-x 1 www www 1724 Jan 20 1997 start-squid
-rwxr-xr-x 1 www www 1724 Jan 20 1997 start-squid.sample
-rwxr-xr-x 1 www www 3068 Jan 20 1997 upgrade-1.0-store.pl
Now I've seen what can happen when you have a httpd.conf owned by the same
user CGI Runs as (all user's cgi has the ability to modify the file)...the
same thing should be possible here. One could easily modify the
start-squid file, or a configuration file, to set up a root shell or
anything else they care to do; since start-squid is initially run as root,
their modifications will be run as root as well.
It might be a good idea to modify BSDi to install them owned by root, just
as it does with apache.
Thank you,
Jonathan A. Zdziarski
Systems Administrator
Netrail Incorporated
jonz@netrail.net
(888) NET-RAIL
The master index of all exploits is available
here (Very large file)
Or you can pick your favorite operating system:
This page is part of Fyodor's exploit
world.
For a free program to automate scanning your network for vulnerable
hosts and services, check out my network mapping tool, nmap. Or try these Insecure.Org resources: