CVE-2001-0964 in Half-Life
Summary
by MITRE
Buffer overflow in client for Half-Life 1.1.0.8 and earlier allows malicious remote servers to execute arbitrary code via a long console command.
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Analysis
by VulDB Data Team • 06/04/2018
The vulnerability identified as CVE-2001-0964 represents a critical buffer overflow flaw within the client software for Half-Life version 1.1.0.8 and earlier releases. This security weakness specifically affects the client-side implementation that processes console commands received from remote servers, creating an exploitable condition that can be leveraged by attackers to gain unauthorized code execution capabilities. The vulnerability stems from inadequate input validation and bounds checking within the client's command processing mechanism, which fails to properly sanitize or limit the length of console commands received from network connections.
The technical implementation of this buffer overflow occurs when the Half-Life client receives a console command from a remote server that exceeds the allocated buffer size. This condition allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow and enabling arbitrary code execution. The flaw operates at the application layer where network communication is processed, making it particularly dangerous as it can be exploited through remote server connections without requiring local system access. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of improper input validation that can lead to privilege escalation and system compromise.
Operationally, this vulnerability creates significant risk for Half-Life users who may unknowingly connect to malicious servers or encounter compromised game servers. Attackers can craft specially formatted console commands that, when executed by the vulnerable client, trigger the buffer overflow condition and execute malicious payloads. The impact extends beyond simple code execution to potentially allow full system compromise, as the malicious code runs with the privileges of the user running the Half-Life client. This vulnerability was particularly concerning in the gaming community where users frequently connect to public servers and may not be aware of server integrity or security measures.
Mitigation strategies for this vulnerability primarily involve updating to patched versions of Half-Life client software, as the issue was resolved through proper bounds checking and input validation implementations. System administrators and users should ensure all Half-Life installations are updated to versions that address this buffer overflow condition. Network security measures including firewall rules and server access controls can help reduce exposure by limiting connections to trusted game servers. The vulnerability also highlights the importance of secure coding practices and input validation in client-server applications, particularly those handling network communications. Organizations should implement regular security assessments and maintain updated software inventories to prevent exploitation of similar vulnerabilities. This issue demonstrates the critical need for proper memory management and bounds checking in networked applications, aligning with ATT&CK technique T1059.007 for command and scripting interpreter and T1203 for Exploitation for Client Execution.