February 2008

Details:
Symantec Security Advisory SYM08-007

28 February, 2008

Symantec's Backup Exec for Windows Server:  Multiple Vulnerabilities in Scheduler

Revision History
None

Severity
Medium

Requirements
Remote Access	Yes
Local Access	No
Authentication Required	Authenticated user involvment required
Exploited publicly available	No

Overview
Vulnerabilities were reported in an ActiveX control that Symantec's Backup Exec for Windows Servers (BEWS) installs with its scheduler. Exploitation of these issues could possibly lead to unauthorized information disclosure, system information corruption or potentially allow arbitrary code execution in the context of the user's browser. However, successful exploitation requires specific conditions.

Affected Products

Product	Version	Build	Solution
Symantec Backup Exec for Windows	11d	11.0.6235	Hotfix Available
Symantec Backup Exec for Windows	11d	11.0.7170	Hotfix Available
Symantec Backup Exec for Windows	12	12.0.1364	Hotfix Available

NOTE: ONLY the products and versions listed as affected above are vulnerable to these issues. This issue impacts the Backup Exec media server only. Remote client agents are NOT affected.

How to obtain the patch:
For 32bit Media Servers:
Backup Exec 11.0.6235:http://support.veritas.com/docs/300630
Backup Exec 11.0.7170:http://support.veritas.com/docs/300627
Backup Exec 12.0.1364:http://support.veritas.com/docs/300632

For 64bit Media Servers:
Backup Exec 11.0.6235:http://support.veritas.com/docs/300631
Backup Exec 11.0.7170:http://support.veritas.com/docs/300628
Backup Exec 12.0.1364:http://support.veritas.com/docs/300633


To which versions of Backup Exec can this hotfix be applied?

This hotfix can only be applied to the following versions of Backup Exec:
Backup Exec 11d for Windows Servers revision 6235 with Service Pack 2
Backup Exec 11d for Windows Servers revision 7170 with Service Pack 2
Backup Exec 12.0 for Windows Servers revision 1364

Details
Symantec was alerted to multiple vulnerabilities consisting of stack overflows and unsafe method calls that Secunia Research discovered in an ActiveX control, installed with BEWS as a part of the scheduler component. Although this control was not intended to be called via an external web browser, it failed to properly parse or validate external input.  This improper validation could potentially result in a browser crash or it could possibly permit unauthorized methods calls allowing access to overwrite or corrupt files.  Unauthorized access to the vulnerable control could also result in possible buffer overflows with the potential for malicious code execution in the context of the targeted user's browser.
The impact of this threat is considerably lessened as it would require authorized user involvement in any attempt to compromise the targeted system.  To exploit successfully, an attacker would need to be aware of the exact path to the vulnerable control and be able to effectively entice a user to upload and execute malicious scripts via HTML email or visit a malicious web site hosting malicious code.

Symantec Response
Symantec product engineers have developed and released solutions for this issue through Symantec's LiveUpdate capability and support channels as indicated.
Symantec recommends all customers apply all updates to protect against threats of this nature.
Symantec knows of no exploitation of or adverse customer impact from these issues.  

The patches listed above for affected products are also available from the following location:

Backup Exec 11.0.6235: http://support.veritas.com/docs/300619 
Backup Exec 11.0.7170: http://support.veritas.com/docs/297620 
Backup Exec 12.0.1364: http://support.veritas.com/docs/300287 

Mitigation
Symantec has developed IDS signatures to detect and block attempts to exploit this issue.

Best Practices
As part of normal best practices, Symantec strongly recommends a multi-layered approach to security:

• Run under the principle of least privilege where possible.
• Keep all operating systems and applications updated with the latest vendor patches.
• Users, at a minimum, should run both a personal firewall and antivirus application with current updates to provide multiple points of detection and protection to both inbound and outbound threats.
• Users should be cautious of mysterious attachments and executables delivered via email and be cautious of browsing unknown/untrusted websites or opening unknown/untrusted URL links.
• Do not open unidentified attachments or executables from unknown sources or that you didn't request or were unaware of.
• Always err on the side of caution. Even if the sender is known, the source address may be spoofed.
• If in doubt, contact the sender to confirm they sent it and why before opening the attachment. If still in doubt, delete the attachment without opening it.
  

Credit
Symantec would like to thank JJ Reyes with Secunia Research for reporting these findings and coordinating closely with Symantec as we resolved the issues.


References
The Common Vulnerabilities and Exposures (CVE) initiative has assigned:
CVE-2007-6016 to the buffer overflow issue
CVE-2007-6017 to the unsafe methods issue
These issues are candidates for inclusion in the CVE list (http://cve.mitre.org/ ), which standardizes names for security issues.

SecurityFocus (http://www.securityfocus.com/ ) has assigned Bugtraq ID BID 26904 for the buffer overflows and BID 28008 for the unsafe methods for inclusion in the SecurityFocus vulnerability database.

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