CVE-2007-2031 in 3proxy
Summary
by MITRE
Buffer overflow in the HTTP proxy service for 3proxy 0.5 to 0.5.3g, and 0.6b-devel before 20070413, might allow remote attackers to execute arbitrary code via crafted transparent requests.
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Analysis
by VulDB Data Team • 01/05/2025
The vulnerability identified as CVE-2007-2031 represents a critical buffer overflow flaw within the HTTP proxy service of 3proxy software versions ranging from 0.5 through 0.5.3g and 0.6b-devel prior to the 20070413 build. This issue resides in the proxy service's handling of transparent requests, which are HTTP requests that bypass normal proxy processing and are directly forwarded to target servers. The flaw manifests when the proxy service receives specially crafted HTTP requests that exceed the allocated buffer space, leading to memory corruption that can be exploited by remote attackers. The vulnerability falls under the CWE-121 category of stack-based buffer overflow, where insufficient bounds checking allows attackers to overwrite adjacent memory locations and potentially execute arbitrary code with the privileges of the proxy service process. This type of vulnerability is particularly dangerous in proxy environments where the service typically operates with elevated privileges to handle network traffic between clients and servers.
The technical exploitation of this vulnerability requires attackers to craft HTTP requests that specifically trigger the buffer overflow condition within the proxy's transparent request handling mechanism. When the proxy service processes these malformed requests, the excessive data causes the buffer to overflow and overwrite adjacent memory segments including return addresses and control data. This memory corruption can be leveraged to redirect program execution flow to malicious code injected by the attacker, effectively allowing remote code execution on the affected system. The attack vector is particularly insidious because it operates over standard HTTP traffic, making it difficult to detect through conventional network monitoring. The vulnerability demonstrates poor input validation practices and inadequate memory management within the proxy service, creating an attack surface that directly violates security principles outlined in the software security community's best practices.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete system compromise and potential network infiltration. An attacker who successfully exploits this vulnerability gains the ability to execute arbitrary commands on the proxy server with the same privileges as the proxy service itself, which often includes network access rights and potentially administrative privileges depending on system configuration. The vulnerability affects organizations that rely on 3proxy as their primary HTTP proxy solution, particularly those using transparent proxy modes for content filtering, caching, or network access control. The exploitability of this flaw increases significantly in environments where the proxy service is accessible from untrusted networks, as the attack can be conducted remotely without requiring local system access. Organizations with extensive proxy infrastructure deployments face heightened risk, as compromising a single vulnerable proxy server can potentially provide attackers with access to internal network resources that would otherwise be protected by firewall rules.
Mitigation strategies for CVE-2007-2031 should prioritize immediate software updates to versions that contain the relevant security patches and fixes. System administrators should implement network segmentation to limit access to proxy services and reduce the attack surface, while also deploying intrusion detection systems that can monitor for suspicious HTTP request patterns. The implementation of proper input validation and bounds checking mechanisms should be enforced throughout the proxy service codebase, following secure coding practices that align with industry standards such as the OWASP Secure Coding Practices and the CERT Secure Coding Standards. Additionally, organizations should conduct regular vulnerability assessments and penetration testing to identify similar buffer overflow vulnerabilities in other network services and applications. The ATT&CK framework categorizes this vulnerability under the T1203 technique for Exploitation for Client Execution, highlighting the need for layered defenses including network monitoring, endpoint protection, and regular security updates to prevent exploitation attempts. System hardening measures such as disabling unnecessary proxy features, implementing strict access controls, and maintaining comprehensive audit logs should also be implemented to provide both preventive and detective capabilities against similar vulnerabilities.