CVE-2001-0082 in Firewall-1
Summary
by MITRE
Check Point VPN-1/FireWall-1 4.1 SP2 with Fastmode enabled allows remote attackers to bypass access restrictions via malformed, fragmented packets.
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Analysis
by VulDB Data Team • 12/18/2024
The vulnerability identified as CVE-2001-0082 affects Check Point VPN-1/FireWall-1 version 4.1 SP2 when operating in Fastmode configuration, representing a critical security flaw that undermines the integrity of network access controls. This vulnerability resides within the packet processing mechanisms of the firewall software, specifically when handling fragmented network traffic under Fastmode operations. The issue stems from insufficient validation of packet fragments during the reassembly process, creating a pathway for malicious actors to exploit the system's defenses.
The technical implementation of this vulnerability involves the improper handling of Internet Control Message Protocol (ICMP) and IP fragment reassembly within the Check Point firewall software. When Fastmode is enabled, the system processes packets with reduced overhead and simplified checking mechanisms, which inadvertently creates gaps in packet validation. Attackers can craft specially malformed fragmented packets that exploit these validation gaps, allowing them to bypass access restrictions that should normally be enforced by the firewall. This flaw operates at the network protocol level, specifically targeting the IP fragmentation reassembly process where the firewall fails to properly validate the integrity and legitimacy of fragmented packets before processing them.
The operational impact of this vulnerability extends beyond simple access bypass, as it fundamentally compromises the security posture of networks relying on Check Point FireWall-1 for protection. Remote attackers can leverage this weakness to gain unauthorized access to protected network segments, potentially escalating privileges and accessing sensitive data without detection. The vulnerability's remote exploitability means that attackers do not require physical access to the network infrastructure, making it particularly dangerous for organizations with distributed networks or remote access requirements. The Fastmode configuration, designed for performance optimization, becomes a security liability when it disables critical validation checks that would normally prevent such attacks.
Mitigation strategies for this vulnerability require immediate implementation of several security measures to protect affected systems. Organizations should disable Fastmode configuration on affected Check Point FireWall-1 systems until proper patches are applied, as this configuration directly enables the exploit conditions. The most effective remediation involves applying the official Check Point security patches and updates that address the packet validation gaps in the fragmentation handling code. Network administrators should also implement additional monitoring and logging of fragmented packet traffic to detect potential exploitation attempts. From a compliance perspective, this vulnerability aligns with CWE-119 which addresses weaknesses in memory handling and improper validation of input data. The attack vector corresponds to techniques described in the ATT&CK framework under network infiltration and privilege escalation categories, specifically targeting the network boundary protection mechanisms that should prevent unauthorized access to internal network resources.
This vulnerability demonstrates the inherent risks of performance optimization configurations that compromise security validation processes, highlighting the importance of maintaining robust input validation even when implementing efficiency improvements. The flaw represents a classic example of how security controls can be inadvertently weakened by optimization features, creating attack surfaces that malicious actors can exploit to bypass fundamental network protection mechanisms. Organizations must balance performance requirements with security assurances, particularly when implementing features like Fastmode that reduce the granularity of packet inspection and validation. The vulnerability also underscores the necessity of thorough security testing of network infrastructure components, especially those that modify standard protocol handling behavior to optimize performance.