CVE-2001-1431 in Firewall Appliance
Summary
by MITRE
Nokia Firewall Appliances running IPSO 3.3 and VPN-1/FireWall-1 4.1 Service Pack 3, IPSO 3.4 and VPN-1/FireWall-1 4.1 Service Pack 4, and IPSO 3.4 or IPSO 3.4.1 and VPN-1/FireWall-1 4.1 Service Pack 5, when SYN Defender is configured in Active Gateway mode, does not properly rewrite the third packet of a TCP three-way handshake to use the NAT IP address, which allows remote attackers to gain sensitive information.
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Analysis
by VulDB Data Team • 11/15/2024
The vulnerability described in CVE-2001-1431 affects Nokia firewall appliances running specific versions of IPSO and VPN-1/FireWall-1 software when SYN Defender is configured in Active Gateway mode. This represents a significant security flaw in network traffic handling that directly impacts the integrity of NAT (Network Address Translation) operations within enterprise firewall environments. The issue stems from improper packet handling during TCP connection establishment processes, specifically affecting the third packet of the TCP three-way handshake mechanism that is fundamental to internet communication protocols.
The technical flaw manifests when the firewall appliance fails to properly rewrite the third packet of a TCP three-way handshake to use the NAT IP address as intended. This occurs specifically within the Active Gateway mode configuration of SYN Defender, which is designed to protect against SYN flood attacks by managing TCP connection states. The failure in packet rewriting creates a situation where sensitive information can be exposed to remote attackers who exploit the inconsistency between the original source IP address and the translated NAT address. This vulnerability operates at the network layer and directly impacts the security controls that protect internal network resources from external threats.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially compromise the entire network security posture of organizations relying on these Nokia firewall appliances. Attackers can leverage this flaw to gain unauthorized access to sensitive network information, potentially leading to further exploitation opportunities including lateral movement within the network infrastructure. The vulnerability affects organizations using specific versions of IPSO 3.3, 3.4, and 3.4.1 along with corresponding VPN-1/FireWall-1 service packs, making it particularly concerning for enterprises that have not yet updated their security infrastructure. This weakness undermines the fundamental security guarantees that NAT and firewall systems are designed to provide, creating potential attack vectors for man-in-the-middle scenarios and connection hijacking attempts.
Organizations affected by this vulnerability should immediately implement mitigations including updating to patched versions of the affected software, disabling SYN Defender in Active Gateway mode if not essential, and monitoring network traffic for anomalous patterns that might indicate exploitation attempts. The vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a significant deviation from the expected behavior of network security appliances. From an ATT&CK framework perspective, this vulnerability maps to techniques involving information gathering and initial access, as attackers can use the exposed information to plan more sophisticated attacks against the network infrastructure. Security professionals should also consider implementing additional monitoring controls and network segmentation strategies to limit the potential impact of this vulnerability while awaiting proper software updates.
The root cause of this vulnerability demonstrates the complexity involved in implementing security features like SYN Defender while maintaining proper NAT functionality. The improper packet rewriting mechanism fails to maintain consistency between the original connection parameters and the translated addresses, creating a security boundary failure that violates fundamental principles of network security architecture. This flaw highlights the importance of thorough testing and validation of security features, particularly those designed to protect against specific attack vectors while maintaining proper network functionality. Organizations should conduct comprehensive security assessments of their firewall configurations and ensure that all security controls operate correctly in conjunction with each other to prevent similar vulnerabilities from compromising their defensive infrastructure.