KB17953 - Vulnerabilities in the PDF distiller of the Attachment Service for BES

hdawg · #1 (**permalink**) 04-21-2009, 10:23 PM

KB17953 - Vulnerabilities in the PDF distiller of the BlackBerry Attachment Service for the BlackBerry Enterprise Server

Environment

BlackBerry® Enterprise Server software version 4.1 Service Pack 3 (4.1.3) through 4.1 Service Pack 6 (4.1.6)
BlackBerry® Professional Software 4.1 Service Pack 4 (4.1.4)

Note

This advisory does not replace KB15766 and KB17118, which describe earlier, similar vulnerabilities. For the convenience of affected customers, the fixes for KB15766 and KB17118 are included in the software update provided for the new vulnerabilities described in this security advisory. Customers affected by the issues described in this advisory should also review KB15766 and KB17118 to review how they are protected from the vulnerability described in that advisory after applying either the updates provided in KB15766 and KB17118, or the one provided in this advisory.

Overview

This advisory describes security issues that the BlackBerry Attachment Service component of the BlackBerry Enterprise Server software is susceptible to. The issues relate to the handling of malformed and possibly malicious PDF files.

Issue Severity: These vulnerabilities each have a Common Vulnerability Scoring System (CVSS) score of 9.3.

Issue Status: Vulnerability confirmed. Software containing security update released.
Recommendation: Complete the resolution actions documented in this advisory.

References:

Reference	Value
Related BlackBerry security advisories	KB15766, KB17118

Problem

Multiple security vulnerabilities exist in the PDF distiller of some released versions of the BlackBerry Attachment Service. These vulnerabilities could enable a malicious individual to send an email message containing a specially crafted PDF file, which when opened for viewing on a BlackBerry smartphone, could cause memory corruption and possibly lead to arbitrary code execution on the computer that hosts the BlackBerry Attachment Service.

Resolution

RIM has issued an interim security software update that resolves this vulnerability in affected versions of the BlackBerry Enterprise Server software and BlackBerry Professional Software.
For BlackBerry Enterprise Server

Visit http://www.blackberry.com/go/serverdownloads to download and install Interim Security Software Update 3 for affected BlackBerry Enterprise Server software versions.

OR

For BlackBerry Enterprise Server for Microsoft Exchange or Lotus Domino, visit http://www.blackberry.com/go/serverdownloads to download and install version 4.1.6 MR5 or later.

For BlackBerry Professional Software
Visit BlackBerry - PDA Software Downloads - Support & Services at BlackBerry.com to obtain Interim Security Software Update 3 for affected BlackBerry Professional Software versions.

Workaround

Note: As a mobile device best practice, Research In Motion (RIM) recommends that BlackBerry smartphone users open attachments from trusted sources only.

Prevent the BlackBerry Attachment Service from processing PDF files in a BlackBerry Enterprise Server environment

You can prevent the BlackBerry Attachment Service from processing PDF files by editing the list of file format extensions that the BlackBerry Attachment Service opens, and then preventing the PDF attachment distiller from running on the BlackBerry Attachment Service.

To remove the PDF file extension from the list of supported file format extensions, complete the following actions:

From the Windows Desktop, open the BlackBerry Server Configuration tool.
Click the Attachment Server tab.
In the Format Extensions field, delete pdf: from the colon–delimited list of extensions.
Click Apply.
Click OK.

Until you prevent the PDF attachment distiller from running, the BlackBerry Attachment Service still detects a PDF file with a renamed extension (in other words, its extension is not .pdf) and attempts to process the file automatically. To prevent the PDF attachment distiller from running, complete the following actions:

On the Windows Desktop, open the BlackBerry Server Configuration tool.
Click the Attachment Server tab.
In the Configuration Option drop-down list, select Attachment Server.
In the Distiller Settings section, next to the distiller name Adobe PDF, clear the check box in the Enabled column.
Click Apply.
Click OK.
On the Windows Desktop, inAdministrative Tools, open Services.
Right-click BlackBerry Attachment Service and click Stop.
Right-click BlackBerry Attachment Service and click Start.
Close Services.

In Microsoft Exchange and Novell GroupWise environments, complete the following additional steps:

On the Windows Desktop, inAdministrative Tools, open Services.
Right-click BlackBerry Dispatcher and click Stop.
Right-click BlackBerry Dispatcher and click Start.
Close Services.

Note: Restarting BlackBerry Enterprise Server services might delay message delivery to BlackBerry devices. For more information, see KB04789.

In IBM Lotus Domino environments, complete the following additional steps:

Open the Lotus Domino Administrator.
Click the Server tab.
Click the Status tab
Click Server Console.
In the Domino Command field, type tell BES quit and press ENTER.
In the Domino Command field, type load BES and press ENTER.
Close the Lotus Domino Administrator.

Additional Information

You can install the BlackBerry Attachment Service on a remote computer and then place that computer on its own network segment to prevent the spread of potential attacks from the BlackBerry Attachment Service to another computer within your organization’s network. In a segmented network, attacks are isolated and contained on a single area of the network. Using segmented network architecture is designed to improve the security and performance of the BlackBerry Attachment Service network segment by filtering out attachment data that is not destined for other network segments. For more information about placing the BlackBerry Enterprise Solution components in a network architecture that is segmented to prevent the spread of potential malware attacks, see Placing the BlackBerry Enterprise Solution in a Segmented Network.

CVSS is a vendor agnostic, industry open standard designed to convey the severity of vulnerabilities. CVSS scores may be used to determine the urgency for update deployment within an organization. CVSS scores range from 0.0 (no vulnerability) to 10.0 (critical). RIM uses CVSS in vulnerability assessments to present an immutable characterization of security issues. RIM assigns all security relevant issues a non-zero score.

Visit www.blackberry.com/security for more information on BlackBerry security.

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