CVE-2012-0804 in CVS
Summary
by MITRE
Heap-based buffer overflow in the proxy_connect function in src/client.c in CVS 1.11 and 1.12 allows remote HTTP proxy servers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted HTTP response.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/03/2025
The vulnerability identified as CVE-2012-0804 represents a critical heap-based buffer overflow within the CVS (Concurrent Versions System) version control software, specifically within the proxy_connect function located in the src/client.c source file. This flaw affects CVS versions 1.11 and 1.12, creating a significant security risk that can be exploited by remote HTTP proxy servers to compromise system integrity. The vulnerability stems from inadequate input validation and memory management practices within the proxy connection handling code, where the software fails to properly bounds-check data received from HTTP proxy responses before processing them in memory structures.
The technical implementation of this vulnerability involves the proxy_connect function's handling of HTTP response data that flows through the CVS client when establishing connections through HTTP proxies. When a malicious HTTP proxy server sends a crafted response containing oversized or malformed data, the function attempts to allocate heap memory for processing this data without sufficient validation of the response size or content. This memory allocation failure creates a buffer overflow condition that can overwrite adjacent memory locations, potentially corrupting program execution flow. The heap-based nature of the overflow means that the vulnerability manifests through heap memory corruption rather than stack-based exploitation, making it particularly challenging to detect and exploit reliably. The flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation leading to memory corruption vulnerabilities.
The operational impact of CVE-2012-0804 extends beyond simple denial of service to potentially enabling remote code execution, making it a severe security concern for organizations relying on CVS for version control operations. When exploited, the vulnerability can cause the CVS client application to crash and terminate unexpectedly, resulting in service disruption for development teams and potentially exposing the system to further compromise. The possibility of arbitrary code execution through this vulnerability means that attackers could gain unauthorized access to systems running vulnerable CVS clients, potentially leading to complete system compromise. This threat is particularly concerning in enterprise environments where CVS is used extensively for source code management and where proxy servers are commonly deployed in network architectures. The vulnerability affects both the availability and integrity of version control systems, potentially allowing attackers to manipulate or corrupt source code repositories.
Organizations should prioritize immediate remediation of CVE-2012-0804 by upgrading to patched versions of CVS, as the vulnerability has been addressed through software updates that include proper input validation and memory management fixes. System administrators should also implement network segmentation and proxy server monitoring to detect and prevent exploitation attempts, particularly focusing on HTTP proxy configurations that may be vulnerable to this attack vector. The mitigation strategy should include disabling unnecessary proxy functionality when not required and implementing strict input validation at network boundaries. Security teams should monitor for indicators of compromise related to this vulnerability, including unexpected process crashes or unusual network traffic patterns when CVS clients interact with proxy servers. Additionally, regular security assessments of version control systems should be conducted to identify and remediate similar vulnerabilities that may exist in other software components. The vulnerability demonstrates the importance of proper memory management practices and input validation in networked applications, aligning with ATT&CK technique T1203 for legitimate credential use and T1059 for command and scripting interpreter usage that may result from successful exploitation.