CVE-2000-1183 in Socks 5
Summary
by MITRE
Buffer overflow in socks5 server on Linux allows attackers to execute arbitrary commands via a long connection request.
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Analysis
by VulDB Data Team • 04/07/2019
The vulnerability described in CVE-2000-1183 represents a critical buffer overflow flaw in SOCKS5 server implementations running on linux systems. This issue stems from inadequate input validation within the network proxy server software that handles SOCKS5 protocol connections. The flaw occurs when the server receives a connection request containing an excessively long string that exceeds the allocated buffer space, creating a condition where adjacent memory locations become overwritten with attacker-controlled data. This particular vulnerability demonstrates the classic characteristics of a stack-based buffer overflow as defined by CWE-121, where insufficient bounds checking allows malicious input to corrupt program execution flow. The attack vector specifically targets the SOCKS5 protocol implementation, which is commonly used for secure network connections and proxy services, making this vulnerability particularly dangerous in environments where such services are deployed.
The technical exploitation of this buffer overflow vulnerability enables remote attackers to execute arbitrary code on the affected system with the privileges of the running SOCKS5 server process. When an attacker sends a malformed connection request containing excessive data, the server's buffer management fails to properly handle the overflow condition, leading to potential memory corruption that can be leveraged to redirect program execution. The vulnerability's impact extends beyond simple denial of service to full system compromise, as the attacker can inject and execute malicious code within the context of the proxy service. This type of vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation, as successful exploitation typically requires the attacker to gain initial access and then leverage the compromised service for further system control. The root cause lies in the server's failure to implement proper input length validation and memory boundary checking during the processing of SOCKS5 connection requests.
The operational impact of CVE-2000-1183 is severe and multifaceted, particularly in enterprise environments where SOCKS5 proxy services are commonly deployed for network security and access control. Organizations utilizing vulnerable SOCKS5 servers face significant risks including complete system compromise, data exfiltration, and potential lateral movement within their network infrastructure. The vulnerability's remote exploitability means that attackers can target systems without requiring local access, making it an attractive target for automated scanning and exploitation campaigns. Network security teams must consider the broader implications of such vulnerabilities, as compromised SOCKS5 servers can serve as entry points for attackers to establish persistent access to internal network resources. The vulnerability also impacts the integrity of network traffic routing and can be used to create covert channels for data exfiltration or command and control communications. Given the widespread deployment of SOCKS5 proxy services in corporate and government environments, this vulnerability represents a substantial risk to network security posture and compliance requirements.
Mitigation strategies for CVE-2000-1183 should prioritize immediate patching of affected SOCKS5 implementations, as this represents the most effective defense against exploitation. Organizations should conduct comprehensive inventory assessments to identify all systems running vulnerable SOCKS5 server software and apply vendor-provided security patches or upgrades. Network segmentation and access controls should be implemented to limit exposure of SOCKS5 services to trusted networks only, reducing the attack surface available to potential attackers. Additional defensive measures include implementing intrusion detection systems to monitor for suspicious connection requests and establishing network monitoring to detect unusual traffic patterns that may indicate exploitation attempts. System hardening practices such as disabling unnecessary services, implementing proper input validation, and configuring memory protection mechanisms should be enforced. The vulnerability also highlights the importance of regular security assessments and vulnerability management programs to identify and remediate similar issues before they can be exploited by adversaries. Organizations should consider implementing network access control lists to restrict access to SOCKS5 services and establish monitoring procedures to detect unauthorized access attempts to proxy services. Regular updates to security software and maintaining current threat intelligence regarding similar vulnerabilities helps ensure comprehensive protection against both known and emerging threats.