CVE-2006-6623 in Antihook
Summary
by MITRE
Sygate Personal Firewall 5.6.2808 relies on the Process Environment Block (PEB) to identify a process, which allows local users to bypass the product s controls on a process by spoofing the (1) ImagePathName, (2) CommandLine, and (3) WindowTitle fields in the PEB.
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Analysis
by VulDB Data Team • 08/10/2018
The vulnerability identified as CVE-2006-6623 represents a critical design flaw in Sygate Personal Firewall version 5.6.2808 that fundamentally undermines the software's ability to properly identify and control system processes. This weakness stems from the firewall's reliance on the Windows Process Environment Block as its primary mechanism for process identification, creating an exploitable vector that allows malicious actors to circumvent security controls through simple manipulation of process metadata.
The technical implementation of this vulnerability exploits the Process Environment Block structure within the Windows operating system, which contains critical process information including ImagePathName, CommandLine, and WindowTitle fields. These fields serve as the primary identifiers for process recognition within the firewall's access control mechanisms. Attackers can manipulate these specific fields within the PEB to present false process information, effectively allowing them to bypass the firewall's process control policies. This technique demonstrates a fundamental misunderstanding of how process identification should be implemented in security software, as it relies on potentially mutable metadata rather than immutable process characteristics.
The operational impact of this vulnerability extends far beyond simple bypass capabilities, as it fundamentally compromises the integrity of the firewall's protection model. Local users who exploit this vulnerability can execute arbitrary processes while remaining undetected by the firewall's monitoring systems, potentially allowing for privilege escalation, data exfiltration, or the establishment of persistent backdoors. The attack vector is particularly concerning because it requires minimal privileges and can be executed through standard user accounts, making it accessible to a wide range of threat actors. This vulnerability essentially renders the firewall's process control features ineffective, as it can be circumvented through simple memory manipulation techniques.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and CWE-254 (Security Features) categories, representing a failure in proper authorization mechanisms and security feature implementation. The attack pattern follows ATT&CK technique T1055 (Process Injection) and T1068 (Local Port Forwarding) by leveraging process manipulation to achieve unauthorized system access. The vulnerability also demonstrates poor adherence to security by design principles, as the firewall should have implemented multiple verification mechanisms rather than relying on a single, easily spoofable identifier. Organizations using this version of Sygate Personal Firewall face significant risk exposure, as the vulnerability allows attackers to bypass all process-based security controls, potentially leading to complete system compromise.
The recommended mitigations for this vulnerability include immediate patching of the Sygate Personal Firewall to a version that addresses this specific flaw, implementation of additional process monitoring solutions that do not rely on PEB manipulation, and deployment of behavioral analysis tools that can detect anomalous process execution patterns. Security administrators should also consider implementing network-based monitoring solutions to detect suspicious activities that might indicate exploitation of this vulnerability, as traditional firewall-based controls would be ineffective. Additionally, organizations should conduct comprehensive security assessments to identify any potential compromise from this vulnerability and ensure that all systems are updated to prevent exploitation through this and similar process spoofing techniques.