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Security Advisories Relating to Symantec Products - Symantec Backup Exec Authentication Bypass and Potential Buffer Overflow


November 19, 2008

Revision History




Remote Access (adjacent network)Yes
Local AccessNo
Authentication RequiredNo
Exploit availableNo

*Proof of concept only


Vulnerabilities were found in the authentication methods for logging onto a Backup Exec Remote Agent for Windows, Linux/Unix, Macintosh and Remote Media Agent for Linux Servers, that could allow an unprivileged user to gain unauthorized access to the application. Once authenticated, the user could further leverage a potential buffer overflow in the data management protocol in an attempt to crash or possibly further compromise the targeted system.

Affected Products

Symantec Backup Exec for Windows Server 12.52213Hotfix Available
Symantec Backup Exec for Windows Server 121364Hotfix Available
Symantec Backup Exec for Windows Server 11d7170Hotfix Available
Symantec Backup Exec for Windows Server 11d6235Hotfix Available

Note: ONLY the product versions and builds listed above as affected are vulnerable to these issues. This impacts the remote agents present on both Media servers and Remote backup hosts.


Tenable Network Security worked with Symantec to identify multiple vulnerability issues in authentication as well as a buffer overflow potential once authenticated on affected Symantec Backup Exec remote agents. An unprivileged but authorized network user could potentially bypass the authentication during the logon process with the Backup Exec remote agents. Access could allow the unauthorized user to retrieve or delete files from the targeted host. Once authenticated, a potential buffer overflow is present in the data management protocol that could allow the unauthorized user to crash or possibly further compromise the targeted system.

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.

Technical documentation concerning this issue is available from:



Symantec has released an IPS signature to detect and block attempts to exploit the buffer overflow (BID 32346).

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.
  • 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.


Symantec would like to thank Renaud Deraison and Nicolas Pouvesle with Tenable Network Security for coordinating on these findings and working closely with Symantec as the issues were resolved.


Security Focus, http://www.securityfocus.com, has assigned a Bugtraq ID (BID) to these issues for inclusion in the Security Focus vulnerability database. BID 32347 has been assigned to the authentication bypass issue and BID 32346 has been assigned to the buffer overflow in the data management protocol.

A CVE Candidate name will be requested from the Common Vulnerabilities and Exposures (CVE) initiative for these issues. This advisory will be revised accordingly upon receipt of the CVE Candidate names. These issues are candidates for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.
Symantec takes the security and proper functionality of our products very seriously. As founding members of the Organization for Internet Safety (OISafety), Symantec supports and follows responsible disclosure guidelines.
Please contact secure@symantec.com if you feel you have discovered a security issue in a Symantec product. A member of the Symantec Product Security team will contact you regarding your submission to coordinate any required response. Symantec strongly recommends using encrypted email for reporting vulnerability information to secure@symantec.com. The Symantec Product Security PGP key can be found at the location below.
Symantec has developed a Product Vulnerability Response document outlining the process we follow in addressing suspected vulnerabilities in our products. This document is available below.

Copyright (c) by Symantec Corp.

Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Product Security. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com


The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Product Security, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.
* Signature names may have been updated to comply with an updated IPS Signature naming convention. See http://www.symantec.com/business/support/index?page=content&id=TECH152794&key=54619&actp=LIST for more information.
Last modified on: November 19, 2008
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