SUMMARY

On-demand scanning with Symantec AntiVirus can be bypassed by denying read access to user files.

AFFECTED PRODUCTS

*SEP 11.x is not vulnerable to this issue. 
** Along with the Best Practices described below, Symantec recommends running Symantec AntiVirus with Tamper Protection enabled and set to “block” mode to further mitigate malicious attacks against the product

ISSUES

Severity

Medium 

MITIGATION

Details

Symantec was notified of a means to potentially bypass an on-demand scan in Symantec AntiVirus. 
If Symantec Tamper protection is disabled, it is possible to potentially bypass scanning by having another entity deny read access to Symantec AntiVirus Protection. 
Should an attacker succeed in passing sufficient specific events to the application, on-demand scans could potentially cease to run. The application will no longer accept the user’s current token degrading the on-demand scan capability while the user remains logged on.

Symantec Response

Symantec product engineers have released MR9 for the Symantec Products listed above that fix the issue. Symantec recommends that all customers apply the latest available updates to protect against threats of this nature. 

Symantec also recommends that the Symantec Tamper Protection be enabled and set to “block” for all customers who use Symantec AntiVirus. 

Symantec is not aware of any exploitation of or adverse customer impact from these issues.

Mitigation

If Customers of Symantec AntiVirus 10.1.x are unable to upgrade to the latest available updates, Symantec recommends that Symantec Tamper Protection be enabled and set to “block” to aid in mitigation of possible threat.

Best Practices

As 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

ACKNOWLEDGEMENTS

Symantec would like to thank Jeffrey Walton and Dr. Brooke Stephens for reporting this issue and coordinating with Symantec for resolution.

REFERENCES

BID: Security Focus, http://www.securityfocus.com, has assigned a Bugtraq ID (BID)38219 to these issues for inclusion in the Security Focus vulnerability database. 

CVE: These issues are candidates for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. The CVE initiative has assigned CVE-2010-0106 to this issue

REVISION

2.19.2010 Updated to note that this issue requires “Local Access” and cannot be done remotely. 
3.1.2010 Removed and explicitly declared SEP 11.x not vulnerable. Added Dr. Brooke Stevens as one of the finders. 
3.2.2010 Removed references to SEP 11.x, clarified questions on tamper protection.