Research in Motion (RIM) has acknowledged a critical security flaw in the way its BlackBerry Enterprise Server processes PDF files and warned that hackers can use PDF attachments to launch harmful code.
Here's the skinny on the problem, via RIM's advisory:
The vulnerability could allow a malicious individual to cause buffer overflow errors, which may result in arbitrary code execution on the computer that hosts the BlackBerry Attachment Service. While code execution is possible, an attack is more likely to result in the PDF rendering process terminating before it completes. In the event of such an unexpected process termination, the PDF rendering process will restart automatically but will not resume processing the same PDF file.
Successful exploitation of this vulnerability requires a malicious individual to persuade a BlackBerry smartphone user to open a specially crafted PDF file on a BlackBerry smartphone that is associated with a user account on a BlackBerry Enterprise Server. The PDF file may be attached to an email message or the BlackBerry smartphone user may retrieve it from a web site using the BlackBerry Browser.
The alert includes information on vulnerable versions of the software and download locations for patches. It also includes workarounds.