CVE-2004-1667 in Halo Combat Evolved
Summary
by MITRE
Off-by-one error in Halo Combat Evolved 1.04 and earlier allows remote attackers to cause a denial of service (server crash) via a long client response.
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Analysis
by VulDB Data Team • 07/08/2017
The vulnerability described in CVE-2004-1667 represents a classic off-by-one error that affected the popular first-person shooter game Halo Combat Evolved version 1.04 and earlier. This type of programming flaw occurs when a program processes one element too many or too few in a sequence, leading to memory access violations. The specific nature of this vulnerability lies in how the game's multiplayer server handles client responses during network communication, where insufficient bounds checking allows malicious input to trigger unexpected behavior. Such errors fall under the CWE-129 category of Improper Validation of Array Index, which is a well-documented weakness in software security practices.
The technical exploitation of this vulnerability involves crafting a specially formatted client response that exceeds the expected buffer size by exactly one byte, triggering the off-by-one condition. When the server processes this malformed response, it attempts to access memory locations beyond the allocated buffer boundaries, resulting in a segmentation fault or access violation that crashes the game server. This type of memory corruption vulnerability is particularly dangerous in networked environments where servers are constantly processing inputs from multiple clients. The vulnerability demonstrates poor input validation practices and inadequate bounds checking mechanisms that are fundamental to secure programming principles.
From an operational perspective, this vulnerability creates a significant risk for game servers and online gaming platforms that rely on Halo Combat Evolved's multiplayer functionality. Attackers can leverage this flaw to perform denial of service attacks against legitimate game servers, disrupting gameplay for all connected users and potentially causing revenue loss for game operators. The impact extends beyond simple service disruption as server crashes can lead to data loss, player frustration, and damage to the game's reputation. The vulnerability is particularly concerning because it requires minimal technical expertise to exploit and can be automated, making it attractive to malicious actors seeking to disrupt online gaming communities. This aligns with ATT&CK technique T1499.004 for Network Denial of Service, which involves causing service unavailability through network-based attacks.
The mitigation strategies for this vulnerability primarily involve applying the official patch released by 343 Industries, which corrected the buffer overflow condition in the client response handling code. System administrators should implement regular security updates and maintain current versions of all gaming software to prevent exploitation. Additionally, network monitoring solutions should be deployed to detect unusual traffic patterns that might indicate exploitation attempts. Input validation measures including proper bounds checking and buffer size enforcement should be implemented at all levels of network communication. Organizations should also consider network segmentation and access controls to limit exposure of gaming servers to untrusted networks. The vulnerability highlights the importance of thorough testing and code review processes, particularly for networked applications where input validation is critical for preventing exploitation. Security teams should maintain awareness of known vulnerabilities through vulnerability databases and implement proactive patch management procedures to protect against similar issues in other software components.