CVE-2002-0414 in FreeBSD
Summary
by MITRE
KAME-derived implementations of IPsec on NetBSD 1.5.2, FreeBSD 4.5, and other operating systems, does not properly consult the Security Policy Database (SPD), which could cause a Security Gateway (SG) that does not use Encapsulating Security Payload (ESP) to forward forged IPv4 packets.
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Analysis
by VulDB Data Team • 04/13/2019
The vulnerability described in CVE-2002-0414 represents a critical flaw in IPsec implementations derived from the KAME project that affected multiple operating systems including NetBSD 1.5.2 and FreeBSD 4.5. This security weakness stems from improper handling of the Security Policy Database (SPD) within IPsec gateways, creating a significant bypass mechanism that undermines the fundamental security assurances provided by IPsec protocols. The issue specifically impacts Security Gateways that do not utilize Encapsulating Security Payload (ESP) for packet protection, exposing these systems to potential packet forgery attacks that could compromise network integrity and confidentiality.
The technical flaw manifests in the improper consultation of the Security Policy Database during packet processing, where the system fails to adequately validate incoming packets against established security policies before forwarding them. This failure creates a pathway where forged IPv4 packets can be accepted and transmitted through the security gateway without proper authentication or authorization checks. The vulnerability exploits the gap between the IPsec implementation's expectations and its actual behavior when processing packets that do not conform to ESP requirements, allowing malicious actors to bypass security controls that should prevent unauthorized packet forwarding.
The operational impact of this vulnerability is substantial as it fundamentally undermines the trust model that IPsec is designed to establish between network entities. Security gateways that rely on IPsec for traffic filtering and policy enforcement become vulnerable to packet forgery attacks, potentially allowing unauthorized access to protected network segments. An attacker could leverage this weakness to inject forged packets into the network, potentially disrupting services or gaining unauthorized access to sensitive information, particularly in environments where IPsec is used to secure communications between different security domains.
This vulnerability aligns with CWE-284, which addresses improper access control in security systems, and represents a failure in proper privilege and access control mechanisms within the IPsec implementation. The flaw also relates to ATT&CK technique T1046, which involves network service scanning and exploitation of network infrastructure, as attackers could potentially use this weakness to manipulate network traffic flows. Organizations implementing IPsec security policies in environments using affected operating systems face increased risk of security breaches, particularly in scenarios where packet filtering and traffic control are critical for maintaining network security boundaries.
The recommended mitigations include updating to patched versions of the affected operating systems, implementing additional network monitoring to detect anomalous packet behavior, and configuring proper access controls to limit exposure. Security administrators should also consider implementing redundant security measures such as firewall rules and intrusion detection systems to compensate for the weakened IPsec implementation. Regular security audits and vulnerability assessments should be conducted to ensure that IPsec implementations maintain proper policy enforcement and that security gateways operate as intended without allowing forged packets to bypass established security controls.