The saveForwardAttachments procedure in the Compose Mail functionality in vtiger CRM 5.0.4 allows remote authenticated users to execute arbitrary code by composing an e-mail message with an attachment filename ending in (1) .php in installations based on certain Apache HTTP Server configurations, (2) .php. on Windows, or (3) .php/ on Linux, and then making a direct request to a certain pathname under storage/.
http://www.vupen.com/english/advisories/2009/2319
http://www.exploit-db.com/exploits/9450