For the second time in as many weeks, Research In Motion Ltd. (RIM) is acknowledging that its BlackBerry Enterprise Server is vulnerable to attack.
This time, the problem is that attackers could use a corrupt Portable Network Graphics (PNG) file to block a user's ability to view attachments. It could also be exploited to launch malicious code on the BlackBerry Attachment Service component of the server, an add-on that enables BlackBerry users to open and view e-mail attachments on their devices.
The vulnerability has been reported in version 4.0 Service Pack 2.
As a workaround, administrators "can exclude PNG images from being processed by the attachment service in the BlackBerry Enterprise Server, or disable the attachment service completely," the vendor said.
Last week, RIM acknowledged that attackers could exploit flaws in BlackBerry Enterprise Server to cause a denial of service. Danish vulnerability clearinghouse Secunia issued its own advisory describing two problems:
- An error in how malformed TIFF image attachments are handled can be exploited to prevent a BlackBerry user from viewing attachments.
- An error in how Server Routing Protocol (SRP) packets are handled can be exploited to disrupt the communication between the BlackBerry Enterprise Server and BlackBerry Router service, potentially causing a denial of service.
Secunia noted that for successful exploitation, the attacker must connect to the BlackBerry Server/Router via TCP port 3101.
As a workaround, RIM recommended ensuring TIFF images aren't processed by the attachment service and/or disabling the image attachment distiller. The vendor added that the BlackBerry Enterprise Server and the BlackBerry Router should be placed behind the firewall in a trusted network segment.