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Security Advisories Relating to Symantec Products - Symantec Backup Exec Man-in-The-Middle


May 26, 2011


Revision History




CVSS v2 : 6.5

Impact : 10

Exploitability : 2.5

CVSS v2 Vector : (AV: A/AC: H/Au: S/C: C/I: C/A: C)


Symantec Backup Exec is vulnerable to man-in-the-middle (MiTM) attack due to weakness in communication protocol implementation and lack of validation of identity information exchanged between media server and remote agent.

Affected Products





Symantec Backup Exec for Windows Servers

11.0, 12.0, 12.5


Upgrade to Symantec Backup Exec 2010 R3

Symantec Backup Exec 2010

13.0, 13.0 R2


Upgrade to Symantec Backup Exec 2010 R3



Symantec was notified of a MiTM issue in the manner in which communication protocols are implemented between Backup Exec media server and remote agent. The issue is a result of lack of validation of remote agent identity information exchanged between media server and remote agent. Successful exploitation may result in privilege escalation enabling an attacker to execute post authentication NDMP commands. Successful exploitation requires the attacker to be an authorized user on the network or have unauthorized presence on an authorized system on the network.


Symantec Response
Symantec product engineers verified that the vulnerability exists in the versions of Backup Exec indicated above.

Symantec has released Symantec Backup Exec 2010 R3 which establishes trust between Backup Exec remote agent and Backup Exec media server before exchanging any sensitive information. Symantec recommends customers upgrade to this release of Symantec Backup Exec which addresses the concern.

Symantec knows of no exploitation of or adverse customer impact from this issue.


Update Information

Customers may obtain Symantec Backup Exec 2010 R3 from their normal support/download locations.

Best Practices
As a part of normal best practices, Symantec strongly recommends:

  • Restrict access to administration or management systems to privileged users.
  • Restrict remote access, if required, to trusted/authorized systems only.
  • Run under the principle of least privilege where possible to limit the impact of exploit by threats.
  • Keep all operating systems and applications updated with the latest vendor patches.
  • Follow a multi-layered approach to security. Run both firewall and anti-malware applications, at a minimum, to provide multiple points of detection and protection to both inbound and outbound threats.
  • Deploy network and host-based intrusion detection systems to monitor network traffic for signs of anomalous or suspicious activity. This may aid in detection of attacks or malicious activity related to exploitation of latent vulnerabilities


Symantec credits Nibin Varghese of iViZ Security, for identifying this issue and working with us while Symantec fixed the issue.


Security Focus,
http://www.securityfocus.com, has assigned Bugtraq ID (BID) 47824 to identify this issue for inclusion in the Security Focus vulnerability database.


CVE: This issue is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. CVE-2011-0546 has been assigned to this issue.




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: May 26, 2011
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