CVE-2005-0657 in CProxy
Summary
by MITRE
Directory traversal vulnerability in Computalynx CProxy 3.3.x and 3.4.x through 3.4.4 allows remote attackers to read arbitrary files or cause a denial of service (application crash) via a .. (dot dot) in an HTTP request.
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Analysis
by VulDB Data Team • 05/30/2019
The directory traversal vulnerability identified in Computalynx CProxy versions 3.3.x through 3.4.4 represents a critical security flaw that enables remote attackers to access arbitrary files on the target system. This vulnerability specifically manifests when the application processes HTTP requests containing .. (dot dot) sequences in file paths, allowing malicious actors to navigate beyond the intended directory structure and access protected resources. The flaw stems from inadequate input validation and path sanitization within the proxy server's file handling mechanisms, creating an exploitable condition that violates fundamental security principles of access control and resource isolation.
The technical implementation of this vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. When an attacker submits a malformed HTTP request containing directory traversal sequences, the proxy server fails to properly validate the requested path before processing the file access operation. This allows the attacker to construct malicious paths that bypass normal file access controls and potentially read sensitive system files, configuration data, or user information. The vulnerability can also be leveraged to cause denial of service conditions by triggering application crashes through carefully crafted path sequences that may lead to buffer overflows or invalid memory access patterns.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential system compromise and service disruption. Remote attackers can exploit this weakness to access critical system files including password databases, configuration files, and application data that should remain protected. The ability to cause application crashes through malformed requests also presents a significant denial of service threat, potentially disrupting proxy services and affecting legitimate users who depend on the system for network access and content filtering. This vulnerability particularly affects organizations using Computalynx CProxy as a web filtering or caching solution, where unauthorized access to sensitive information could lead to data breaches and compliance violations.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected systems to address the root cause through proper input validation and path sanitization. Organizations should implement network segmentation and access controls to limit exposure of vulnerable proxy servers to untrusted networks, while also deploying web application firewalls to detect and block malicious traversal attempts. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other network services, with particular attention to applications handling file operations and path resolution. The remediation process must include comprehensive testing to ensure that the patch does not introduce regressions in legitimate proxy functionality while maintaining the intended security controls. Additionally, system administrators should monitor for exploitation attempts through log analysis and implement automated alerting mechanisms to detect suspicious directory traversal patterns in real-time network traffic.