The Research in Motion (RIM) BlackBerry Attachment Service contains a vulnerability in the way the service handles PNG files. By causing the service to render a specially crafted PNG file and convincing a user to view the file on a BlackBerry Handheld device, an attacker could execute arbitrary code or cause a denial of service to the Attachment Service.
The BlackBerry Attachment Service is a component of the BlackBerry Enterprise Server (BES). The BlackBerry Attachment Service renders certain types of files sent as email attachments for display on BlackBerry Handhelds and other BlackBerry client devices. A vulnerability in the way the service renders Portable Network Graphic (PNG) format image files could allow an attacker supplying a specially crafted PNG file to execute arbitrary code or cause the service to stop functioning. A user must view the attacker-supplied attachment on a BlackBerry Handheld in order to trigger the vulnerability.
The underlying vulnerability may be related to the way PNG uses zlib.
By supplying a specially crafted PNG image as an email attachment and convincing a user to view the image on a BlackBerry Handheld, a remote, unauthenticated attacker could execute arbitrary code or cause a denial of service to the Blackberry Attachment Service. The attacker may be able to take control of a vulnerable system.
A denial of service may only affect some users, and the Attachment Service may start new threads immediately or after a specified time period (25 minutes by default).
From RIM Technical Knowledge Center article KB-04756:
For Microsoft Exchange
Install BlackBerry Enterprise Server 4.0 Service Pack 3, then install version 4.0 Service Pack 3, Hotfix 1.
For IBM Lotus Domino and Novell GroupWise
Install BlackBerry Enterprise Server 4.0 Service Pack 3.
To obtain the BlackBerry Enterprise Server software, go to www.blackberry.com/Downloads.
Disable PNG processing, image attachment distiller, and/or Attachment Service