CVE-2002-1778 in Norton Personal Firewall
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 04/19/2019
The vulnerability described in CVE-2002-1778 represents a significant weakness in Symantec Norton Personal Firewall 2002's network traffic inspection capabilities. This flaw specifically targets the firewall's port scanning protection mechanisms, which are designed to detect and block malicious network scanning attempts that could indicate reconnaissance activities by attackers. The vulnerability affects the firewall's ability to properly identify and block specific TCP packet combinations that are commonly used in port scanning techniques to map network services and identify potential entry points.
The technical implementation of this vulnerability stems from the firewall's insufficient parsing and analysis of TCP packet headers during network traffic inspection. When attackers employ the specific packet combinations of SYN/FIN, SYN/FIN/URG, SYN/FIN/PUSH, or SYN/FIN/URG/PUSH scans, the Norton Personal Firewall fails to correctly recognize these as potentially malicious scanning patterns. This occurs because the firewall's stateful inspection engine does not properly account for the unusual combinations of TCP flags that are characteristic of these scanning techniques, allowing the traffic to pass through the security layer unimpeded.
From an operational perspective, this vulnerability creates a serious security risk for users of the affected firewall version. Attackers can exploit this weakness to conduct port scans against systems protected by Norton Personal Firewall 2002 without triggering the expected protective measures. This bypass capability undermines the fundamental purpose of personal firewall protection, which is to prevent unauthorized network access and scanning activities that could lead to system compromise. The vulnerability essentially provides attackers with a stealthy method to gather information about network services and potentially identify vulnerable applications or services running on target systems.
The impact of this vulnerability aligns with CWE-119, which addresses weaknesses in memory handling that can lead to security flaws in network protection systems. This weakness specifically manifests in the improper handling of TCP packet flag combinations during network traffic inspection. From an attacker's perspective, this vulnerability maps to techniques described in the MITRE ATT&CK framework under the T1046 category for network service scanning, where adversaries attempt to discover open ports and services on target systems. The bypass of port scan detection mechanisms directly supports the attacker's ability to perform reconnaissance activities without raising security alerts that would normally be triggered by such scanning behavior.
Organizations and individuals using Symantec Norton Personal Firewall 2002 should immediately implement mitigation strategies including updating to the latest firewall version that addresses this vulnerability, implementing additional network monitoring solutions, and configuring alternative security measures such as intrusion detection systems or network segmentation to compensate for the weakened protection. The vulnerability also highlights the importance of proper stateful inspection implementation in network security devices, emphasizing that simple packet filtering approaches may not be sufficient to detect sophisticated scanning techniques that exploit legitimate TCP protocol features in unusual combinations.