CVE-2000-0813 in Firewall-1
Summary
by MITRE
Check Point VPN-1/FireWall-1 4.1 and earlier allows remote attackers to redirect FTP connections to other servers ("FTP Bounce") via invalid FTP commands that are processed improperly by FireWall-1, aka "FTP Connection Enforcement Bypass."
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Analysis
by VulDB Data Team • 04/06/2019
The vulnerability identified as CVE-2000-0813 represents a critical security flaw in Check Point VPN-1 and FireWall-1 versions 4.1 and earlier systems. This weakness specifically targets the firewall's handling of File Transfer Protocol commands and enables malicious actors to exploit improper command processing to redirect FTP connections to unauthorized servers. The vulnerability falls under the category of protocol handling flaws that can be leveraged for unauthorized network access and data exfiltration.
The technical implementation of this vulnerability stems from the improper processing of invalid FTP commands within the FireWall-1 enforcement mechanisms. When the firewall encounters malformed FTP commands, it fails to properly validate or reject these inputs, allowing attackers to manipulate the connection flow. This flaw specifically affects the FTP Bounce attack vector where an attacker can force the firewall to establish connections to arbitrary servers using the firewall's own network resources. The underlying issue resides in the lack of proper input validation and command sanitization within the FTP protocol handling components, creating a pathway for bypassing normal connection enforcement policies.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data compromise and network reconnaissance activities. Attackers can leverage this flaw to redirect FTP traffic to malicious servers, potentially intercepting sensitive data transfers or using the firewall as a pivot point for further network exploration. The vulnerability essentially undermines the fundamental security boundary that firewalls are designed to maintain, allowing external attackers to circumvent network protection mechanisms. This bypass capability can result in unauthorized data access, service disruption, and potential escalation to more severe network compromise scenarios.
Organizations running affected Check Point firewall versions should implement immediate mitigations including upgrading to patched versions of the software, implementing additional network segmentation measures, and monitoring for suspicious FTP traffic patterns. The vulnerability demonstrates the critical importance of proper input validation and protocol handling in network security appliances, aligning with common weakness enumerations such as CWE-20 for improper input validation and CWE-119 for improper restriction of operations within a limited context. From an attack framework perspective, this vulnerability maps to techniques described in the ATT&CK matrix under network infiltration and command and control categories, particularly emphasizing the use of protocol manipulation for bypassing security controls.
The broader implications of this vulnerability highlight the need for comprehensive security testing of protocol handling components within network infrastructure devices. This flaw represents a classic example of how seemingly minor input validation failures can create significant security risks in critical network protection systems. Organizations should conduct thorough security assessments of their firewall configurations and ensure proper patch management procedures are in place to address similar vulnerabilities in other network security appliances. The incident underscores the necessity of robust security testing methodologies that include protocol-level validation and enforcement mechanism auditing to prevent exploitation of similar weaknesses in network security infrastructure.