CVE-2001-1548 in ZoneAlarm
Summary
by MITRE
ZoneAlarm 2.1 through 2.6 and ZoneAlarm Pro 2.4 and 2.6 allows local users to bypass filtering via non-standard TCP packets created with non-Windows protocol adapters.
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Analysis
by VulDB Data Team • 06/15/2024
The vulnerability described in CVE-2001-1548 represents a significant security flaw in ZoneAlarm firewall software versions 2.1 through 2.6 and ZoneAlarm Pro versions 2.4 and 2.6. This issue stems from the software's inadequate handling of non-standard TCP packets that are generated using non-Windows protocol adapters. The vulnerability specifically affects the packet filtering mechanisms that are fundamental to firewall operations, creating a potential attack surface where malicious actors can exploit the software's failure to properly validate incoming network traffic. The flaw manifests when the firewall encounters TCP packets that do not conform to standard Windows networking protocols, allowing these anomalous packets to bypass the intended filtering controls.
The technical root cause of this vulnerability lies in the insufficient validation and processing of network packets within ZoneAlarm's filtering engine. When non-standard TCP packets are transmitted through network interfaces that utilize non-Windows protocol adapters, the firewall software fails to properly inspect or categorize these packets according to its established security policies. This processing gap creates a scenario where the firewall's rule enforcement mechanism becomes ineffective against certain types of network traffic that exploit the software's limited protocol handling capabilities. The vulnerability operates at the network protocol level, specifically targeting the transport layer where TCP packet validation should occur, making it particularly dangerous as it undermines the fundamental security boundary that firewalls are designed to maintain.
From an operational perspective, this vulnerability presents a substantial risk to systems running affected ZoneAlarm versions, as local users can exploit the flaw to circumvent network security controls. The ability to bypass filtering through non-standard packet construction means that attackers who have local access to a system can potentially gain unauthorized network access or disrupt normal security operations. The impact extends beyond simple packet bypass, as this vulnerability could enable more sophisticated attacks such as port scanning, service enumeration, or even direct network infiltration attempts that would otherwise be blocked by the firewall's protection mechanisms. The local user requirement for exploitation suggests that the vulnerability may be used for privilege escalation or lateral movement within a compromised network environment.
The security implications of CVE-2001-1548 align with CWE-119, which addresses weaknesses in memory handling that can lead to buffer overflows and other memory corruption issues, though this particular vulnerability manifests more specifically in protocol handling rather than memory management. This flaw also relates to ATT&CK technique T1071.004, which covers application layer protocol communication, as the vulnerability exploits weaknesses in how the firewall handles network protocols. Organizations should consider this vulnerability in their broader threat modeling and security posture assessments, particularly in environments where local user access is not strictly controlled. The vulnerability demonstrates the critical importance of comprehensive protocol validation in security software and highlights the risks associated with incomplete implementation of network traffic inspection mechanisms.
Mitigation strategies for this vulnerability should include immediate patching of affected ZoneAlarm installations to the latest available versions that address the protocol handling deficiencies. System administrators should also implement additional monitoring and logging of unusual network traffic patterns that might indicate exploitation attempts. Network segmentation and access controls should be strengthened to limit local user privileges and reduce the potential impact of successful exploitation. Organizations should conduct thorough security assessments to identify all systems running vulnerable ZoneAlarm versions and ensure complete remediation. The vulnerability underscores the necessity of robust testing procedures for security software, particularly in validating how applications handle non-standard or malformed network protocols. Regular security updates and vulnerability management processes become critical in preventing exploitation of similar protocol handling flaws in other security products.