The problems, reported to Symantec Corp. by eEye Digital Security, involve several functions of the products but one specific file, SYMDNS.SYS.
Symantec has provided a brief description, stating that fixes for all of the problems are available through its LiveUpdate and technical-support channels.
Products affected include Symantec Client Firewall versions 5.0.0 through 5.1.1; Symantec Client Security 1.0.0, 1.1.0 and 2.0.0; Norton AntiSpam 2004; Norton Internet Security 2002 through 2004; and Norton Internet Security Professional Edition 2002 through 2004.
DNS response is one of the functions listed as having such an error. A malicious response to a DNS request could cause the program to fail or alter the flow of the program. There are also errors in the processing of NetBIOS Name Service responses that could allow remote code execution or denial of service. Since NetBIOS is not a routable protocol, such attacks would have to come from within a network segment.