Vulnerability Note VU#682110

Multiple Symantec firewall products fail to properly process DNS response packets

Original Release date: 13 May 2004 | Last revised: 13 May 2004


There is a vulnerability in multiple Symantec firewall products in which attempts to process a specially crafted Domain Name Service (DNS) response packet could allow an unauthenticated, remote attacker to cause a denial of service condition.


Symantec offers a suite of corporate and consumer security products including a firewall application. The firewall application includes a SYMDNS.SYS driver, which is responsible for validating DNS and NetBIOS Name Service (NBNS) responses. There is a vulnerability in the routine responsible for processing incoming DNS responses. By supplying a DNS packet containing a specially crafted compressed name pointer, an attacker could cause the kernel to enter an infinite loop on the vulnerable system.

According to the Symantec Advisory, the following products are affected:

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)


An unauthenticated, remote attacker could cause a denial of service condition on the vulnerable system. In order to regain functionality, the system may have to be rebooted.


Apply Patch

Symantec recommends that clients running corporate versions of the affected products apply patches obtained through their appropriate support channels.

Use LiveUpdate
Symantec recommends that clients running consumer versions of the affected products use the LiveUpdate feature to ensure all updates are installed. According to Symantec, this can be done as follows:

    • 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

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Symantec CorporationAffected-13 May 2004
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was reported by eEye Digital Security .

This document was written by Damon Morda and based on information contained in the eEye Digital Security Advisory .

Other Information

  • CVE IDs: CAN-2004-0445
  • Date Public: 12 May 2004
  • Date First Published: 13 May 2004
  • Date Last Updated: 13 May 2004
  • Severity Metric: 9.56
  • Document Revision: 7


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