CVE-2007-2952 in filter service
Summary
by MITRE
Multiple stack-based buffer overflows in the filter service (aka k9filter.exe) in Blue Coat K9 Web Protection 3.2.44 with Filter 3.2.32 allow (1) remote attackers to execute arbitrary code via a long HTTP Referer header to the K9 Web Protection Administration interface and (2) man-in-the-middle attackers to execute arbitrary code via an HTTP response with a long HTTP version field.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability identified as CVE-2007-2952 represents a critical stack-based buffer overflow flaw within the Blue Coat K9 Web Protection system's filter service component. This security weakness exists in version 3.2.44 with Filter 3.2.32 and manifests through improper input validation mechanisms that fail to properly bounds-check data received from network sources. The affected component k9filter.exe operates as a core filtering service responsible for processing web traffic and maintaining security policies within the Blue Coat protection framework, making this vulnerability particularly dangerous as it directly impacts the system's ability to process legitimate network communications.
The technical exploitation of this vulnerability occurs through two distinct attack vectors that leverage different HTTP protocol elements to trigger the buffer overflow condition. The first vector involves sending a maliciously crafted HTTP Referer header that exceeds the allocated buffer space within the filter service, while the second vector targets HTTP responses containing excessively long HTTP version fields that similarly overflow the stack memory. Both attack scenarios exploit the fundamental flaw of insufficient input validation where the system does not properly verify the length of incoming data before attempting to copy it into fixed-size memory buffers, creating conditions where attacker-controlled data can overwrite adjacent memory locations including return addresses and function pointers.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with complete system compromise capabilities through remote code execution. When successfully exploited, the buffer overflow allows attackers to inject and execute arbitrary code within the context of the k9filter.exe process, potentially leading to full system takeover, data exfiltration, or persistent backdoor installation. The remote nature of the first attack vector means that adversaries can exploit this vulnerability without requiring physical access to the network infrastructure, while the man-in-the-middle capability of the second vector allows for exploitation during legitimate network traffic interception. This vulnerability particularly affects enterprise environments that rely on Blue Coat K9 Web Protection for content filtering and web security enforcement, potentially compromising the entire organization's network security posture.
Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided security patches, implementing network segmentation to limit exposure, and deploying intrusion detection systems to monitor for exploitation attempts. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow which classifies this as a fundamental memory safety issue that can lead to arbitrary code execution. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1059 Command and Scripting Interpreter and T1071 Application Layer Protocol for exploitation. Network administrators should also consider implementing HTTP header filtering rules and monitoring for unusually long HTTP Referer or version fields as additional defensive measures, while conducting thorough vulnerability assessments to identify any potential exploitation attempts that may have already occurred within their network environments.