CVE-2001-1465 in Superscout Web Filter
Summary
by MITRE
SurfControl SuperScout only filters packets containing both an HTTP GET request and a Host header, which allows local users to bypass filtering by fragmenting packets so that no packet contains both data elements.
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Analysis
by VulDB Data Team • 06/14/2024
The vulnerability identified as CVE-2001-1465 represents a significant flaw in the SurfControl SuperScout web filtering solution that operated under the principle of content-based packet filtering. This security weakness emerged from the software's restrictive approach to examining network traffic, specifically targeting HTTP GET requests combined with Host headers as the primary criteria for filtering decisions. The implementation of this filtering mechanism created a fundamental gap in network security controls that malicious actors could exploit through sophisticated packet manipulation techniques. The vulnerability stems from the software's inability to properly analyze fragmented network packets that do not contain both required elements within a single packet, thereby undermining the intended security posture of the filtering system.
The technical flaw manifests in how SurfControl SuperScout processes and evaluates network packets during the filtering process. The system's design assumes that all relevant HTTP traffic will contain both an HTTP GET request and a Host header within the same packet, which creates a false sense of security for network administrators. When packets are fragmented or constructed in such a way that the GET request and Host header appear in separate packets, the filtering mechanism fails to recognize the complete HTTP transaction. This architectural limitation directly violates the principle of comprehensive traffic inspection and demonstrates a failure in implementing proper stateful packet inspection capabilities. The vulnerability aligns with CWE-1176, which addresses issues related to insufficient packet inspection and incomplete protocol analysis in network security devices.
The operational impact of this vulnerability extends beyond simple bypass capabilities, creating substantial risks for organizations relying on SurfControl SuperScout for web content filtering. Local users with basic network knowledge can exploit this weakness to access restricted websites, bypass corporate security policies, and potentially gain unauthorized access to sensitive resources. The attack vector requires minimal sophistication, as it only necessitates packet fragmentation techniques that are readily available through standard network tools and utilities. This vulnerability undermines the fundamental security assumptions of the filtering system and creates potential pathways for data exfiltration, malicious web access, and insider threats. Organizations may experience unauthorized access to restricted content, compromised network security postures, and potential violations of regulatory compliance requirements for network monitoring and access control.
Mitigation strategies for this vulnerability must address both the immediate exploitation risk and the underlying architectural flaw in the filtering system. Network administrators should implement additional filtering layers beyond SurfControl SuperScout, including stateful inspection firewalls and more robust web proxy solutions that can properly handle fragmented packets. The implementation of network segmentation and additional access controls can help reduce the impact of successful exploitation attempts. Organizations should consider upgrading to more modern filtering solutions that properly implement stateful packet inspection and comprehensive protocol analysis. Security monitoring should include detection of unusual packet fragmentation patterns and unauthorized access attempts. This vulnerability highlights the importance of following security best practices outlined in the ATT&CK framework, particularly those related to network ingress and egress filtering, where the failure to properly inspect network traffic creates exploitable conditions for attackers to bypass security controls. The incident underscores the necessity of conducting thorough security assessments of network filtering solutions to ensure they properly handle various packet construction scenarios and maintain comprehensive protection against sophisticated evasion techniques.