Multiple vulnerabilities in SYMDNS.SYS for Symantec Norton Internet Security and Professional 2002 through 2004, Norton Personal Firewall 2002 through 2004, Norton AntiSpam 2004, Client Firewall 5.01 and 5.1.1, and Client Security 1.0 through 2.0 allow remote attackers to cause a denial of service or execute arbitrary code via (1) a manipulated length byte in the first-level decoding routine for NetBIOS Name Service (NBNS) that modifies an index variable and leads to a stack-based buffer overflow, (2) a heap-based corruption problem in an NBNS response that is missing certain RR fields, and (3) a stack-based buffer overflow in the DNS component via a Resource Record (RR) with a long canonical name (CNAME) field composed of many smaller components.

The SYMDNS.SYS driver in Symantec Norton Internet Security and Professional 2002 through 2004, Norton Personal Firewall 2002 through 2004, Norton AntiSpam 2004, Client Firewall 5.01 and 5.1.1, and Client Security 1.0 through 2.0 allows remote attackers to cause a denial of service (CPU consumption from infinite loop) via a DNS response with a compressed name pointer that points to itself.

Symantec Norton Personal Firewall 2002 allows remote attackers to bypass the portscan protection by using a (1) SYN/FIN, (2) SYN/FIN/URG, (3) SYN/FIN/PUSH, or (4) SYN/FIN/URG/PUSH scan.

Norton Personal Firewall 2002 4.0, when configured to automatically block attacks, allows remote attackers to block IP addresses and cause a denial of service via spoofed packets.

The "block fragmented IP Packets" option in Symantec Norton Personal Firewall 2002 (NPW) does not properly protect against certain attacks on Windows vulnerabilities such as jolt2 (CVE-2000-0305).