CVE-2000-0809 in Firewall-1
Summary
by MITRE
Buffer overflow in Getkey in the protocol checker in the inter-module communication mechanism in Check Point VPN-1/FireWall-1 4.1 and earlier allows remote attackers to cause a denial of service.
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Analysis
by VulDB Data Team • 04/06/2019
The vulnerability identified as CVE-2000-0809 represents a critical buffer overflow flaw within the inter-module communication mechanism of Check Point VPN-1/FireWall-1 version 4.1 and earlier systems. This security weakness resides specifically within the Getkey function of the protocol checker component, which serves as a crucial element in the firewall's inter-module communication architecture. The flaw manifests when the system processes incoming data through the protocol checking mechanism, creating an exploitable condition that can be leveraged by remote attackers to disrupt system operations.
The technical implementation of this vulnerability stems from inadequate input validation within the Getkey function, which fails to properly bounds-check data received through inter-module communication channels. When maliciously crafted input data exceeds the allocated buffer space, it overflows into adjacent memory regions, potentially corrupting critical system structures and causing unpredictable behavior. This type of vulnerability maps directly to CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw operates at the application layer of the network stack, specifically affecting the protocol checker's ability to validate and process communication packets between different modules within the firewall system.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it provides attackers with a mechanism to destabilize the entire firewall infrastructure. Remote attackers can exploit this weakness to cause the system to crash or become unresponsive, effectively rendering the firewall ineffective in protecting network traffic. This disruption can result in complete network exposure, as the firewall's protective capabilities are nullified. The vulnerability's remote exploitability means that attackers do not require physical access or local network presence, making it particularly dangerous in enterprise environments where firewalls serve as primary security perimeters. According to ATT&CK framework category T1499, this vulnerability represents a denial of service attack vector that can be executed remotely, potentially leading to broader system compromise.
Mitigation strategies for CVE-2000-0809 should prioritize immediate patch deployment from Check Point, as the vendor released specific fixes for this vulnerability in subsequent versions of their firewall software. Organizations must implement network segmentation and access controls to limit exposure while patches are deployed, ensuring that only authorized personnel can access affected systems. Network monitoring should be enhanced to detect anomalous traffic patterns that might indicate exploitation attempts, particularly focusing on unusual inter-module communication patterns. Additionally, implementing intrusion detection systems with signatures specifically targeting this vulnerability can provide early warning capabilities. The remediation process should include comprehensive system testing to ensure that patch deployment does not introduce compatibility issues with existing network configurations, and organizations should maintain detailed rollback procedures in case of deployment failures. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network security components that may present analogous attack surfaces.