The Mail Fetch plugin in SquirrelMail 1.4.20 and earlier allows remote authenticated users to bypass firewall restrictions and use SquirrelMail as a proxy to scan internal networks via a modified POP3 port number.
Affected Platforms
Squirrelmail SquirrelmailRedhat Enterprise Linux WorkstationRedhat Enterprise Linux DesktopRedhat Enterprise Linux ServerFedoraproject FedoraApple Mac Os XApple Mac Os X Server