WelcomeEnterpriseSmall BusinessHome & Home OfficePartnersAbout Symantec
May 12, 2004
Symantec Client Firewall Remote Access and Denial of Service Issues

Revision History

Risk Impact

eEye Digital Security notified Symantec Corporation of four vulnerability issues they discovered in the Symantec Client Firewall products for Windows. By properly exploiting these issues, an attacker could render the targeted system inoperable or execute remote code with kernel-level privileges on the targeted system.

Affected Components
Symantec Norton Internet Security and Professional 2002, 2003, 2004
Symantec Norton Personal Firewall 2002, 2003, 2004
Symantec Norton AntiSpam 2004
Symantec Client Firewall 5.01, 5.1.1
Symantec Client Security 1.0, 1.1, 2.0(SCF 7.1)

eEye Digital Security notified Symantec of four vulnerabilities they discovered during product testing on versions of Symantec's client firewall application. eEye Digital Security found three instances where remote KERNEL-level access could potentially be gained. Additionally, they reported a denial of service (DoS) issue that requires a system reboot to regain system utilization.

All issues occur within routines in the SYMDNS.SYS component.

The first issue is a stack overflow in the processing of DNS responses caused by improper bounds checking of external input. Successful exploitation of this issue could result in remote code execution on the targeted system with kernel-level privileges.

The second issue is a stack overflow in the processing of NetBIOS Name Service responses that can result in a memory overwrite. If an attacker could successfully create the conditions required to manipulate this vulnerability they could potentially execute arbitrary code with kernel-level privileges.

The third remote execution issue is a potential heap corruption problem caused by improper bounds checking in the processing of NetBIOS Name Service responses. If an attacker were to successfully exploit this condition, they could possibly execute arbitrary code on the targeted system with kernel-level privileges.

The forth issue is a potential DoS condition caused by improper handling of DNS response packets. Maliciously configured DNS responses can cause the targeted system to halt requiring a system reboot to clear the condition and regain system access.

Symantec Response
Symantec confirmed the vulnerabilities exist in the consumer and corporate Symantec Client Firewall applications as well as in Symantec's Norton AntiSpam 2004 application. Symantec product engineers have developed fixes for the issues and released patches for all impacted products through Symantec LiveUpdate and technical support channels.

Clients running consumer versions of the affected products who regularly run a manual Symantec LiveUpdate should already be protected against this issue. However, to be sure they are fully protected, customers should manually run Symantec LiveUpdate to ensure all available updates are installed.

  • Open any installed Symantec product
  • Click on LiveUpdate in the toolbar
  • Run LiveUpdate until Symantec LiveUpdate indicated that all installed Symantec products are up-to-date
  • Depending on the application, system may require a reboot to effectively update available fixes.

Clients running the corporate versions of Symantec Client Firewall or Symantec Client Security should download and apply patches obtained through their appropriate support channels.

Symantec is not aware of any active attempts against or customer impact from this issue.

The Common Vulnerabilities and Exposures (CVE) initiative has assigned Candidate names to these issues.

Issues one, two and three are assigned under CVE Candidate Name, CAN-2004-0444.

The fourth issue, the Denial of Service in handling of DNS response packets, is assigned CVE Candidate Name, CAN 2004-0445.

These are candidates for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems.

Symantec appreciates the cooperation of the eEye Digital Security research team in identifying 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 the principles of responsible disclosure. Symantec also subscribes to the vulnerability disclosure guidelines outlined by the National Infrastructure Advisory Council (NIAC).

Please contact secure@symantec.com if you feel you have discovered a security issue in a Symantec product. A Symantec Product Security team member will contact you regarding your submission. 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 end of this message.

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.

PDF Symantec Vulnerability Response Policy PGP Symantec Product Vulnerability Management PGP Key

Copyright © 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 Security Response. 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 Security Response, 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.

Last modified on: Monday, 25-Oct-2004 15:28:32 PDT