CVE-2007-1685 in K9 Web Protection
Summary
by MITRE
Buffer overflow in k9filter.exe in BlueCoat K9 Web Protection 3.2.36, and probably other versions before 3.2.44, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a long HTTP GET request to port 2372.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/21/2025
The vulnerability identified as CVE-2007-1685 represents a critical buffer overflow flaw in the k9filter.exe component of BlueCoat K9 Web Protection software version 3.2.36 and earlier releases. This issue affects the web filtering proxy service that operates on port 2372, which is commonly used for communication between client browsers and the filtering appliance. The vulnerability stems from insufficient input validation within the HTTP GET request processing logic, where the application fails to properly bounds-check user-supplied data before copying it into fixed-size buffers. This fundamental flaw creates an exploitable condition that can be leveraged by remote attackers to manipulate memory contents and potentially gain unauthorized system access.
The technical implementation of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios. When an attacker crafts a specially crafted HTTP GET request containing an excessive amount of data in the request line or headers, the k9filter.exe process attempts to store this data in a predetermined memory buffer without adequate size verification. The overflow can overwrite adjacent memory locations including return addresses, function pointers, or other critical control data structures. This memory corruption can result in immediate process termination leading to denial of service conditions or, in more sophisticated exploitation scenarios, allow attackers to inject and execute arbitrary code with the privileges of the affected service account.
From an operational perspective, this vulnerability poses significant risks to organizations relying on BlueCoat K9 Web Protection for network security and content filtering. The remote attack vector means that adversaries do not require physical access or local network presence to exploit the flaw, making it particularly dangerous in enterprise environments where web filtering appliances are exposed to internet traffic. The potential for remote code execution creates opportunities for attackers to establish persistent access, escalate privileges, or use the compromised system as a launch point for further attacks within the network infrastructure. The service running on port 2372 typically operates with elevated privileges to perform its filtering functions, increasing the impact of successful exploitation. Organizations may experience service disruption, data loss, or complete system compromise depending on the execution environment and the attacker's objectives.
Mitigation strategies for CVE-2007-1685 should prioritize immediate software updates to BlueCoat K9 Web Protection versions 3.2.44 or later, which contain the necessary patches addressing the buffer overflow condition. Network administrators should implement firewall rules to restrict access to port 2372 from untrusted networks and consider implementing additional monitoring for suspicious HTTP GET requests that exceed normal size parameters. The principle of least privilege should be enforced by running the k9filter.exe service with minimal required permissions and ensuring proper system hardening measures are in place. Security teams should also deploy intrusion detection systems capable of identifying malformed HTTP traffic patterns and establish incident response procedures for handling potential exploitation attempts. Organizations should conduct thorough vulnerability assessments to identify all instances of the affected software and ensure comprehensive patch management processes are in place to prevent similar vulnerabilities from remaining unaddressed in the future. This vulnerability demonstrates the critical importance of input validation and memory safety practices in network security appliances, aligning with ATT&CK technique T1203 for legitimate credential use and T1059 for command and scripting interpreter usage in exploitation scenarios.