CVE-2003-1431 in Unreal Engine
Summary
by MITRE
Buffer overflow in Epic Games Unreal Engine 226f through 436 allows remote attackers to cause a denial of service (crash) via a long host string in the Unreal URL.
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Analysis
by VulDB Data Team • 12/15/2024
The vulnerability identified as CVE-2003-1431 represents a critical buffer overflow flaw within the Epic Games Unreal Engine versions ranging from 226f through 436. This security weakness specifically manifests when the engine processes Unreal URLs containing excessively long host strings, creating a condition where memory boundaries are exceeded during string handling operations. The flaw operates at the core of network communication protocols used by the Unreal Engine for establishing multiplayer connections and accessing remote game servers.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the Unreal URL parsing component of the engine. When a remote attacker crafts a malicious Unreal URL with an abnormally long host string, the engine fails to properly bounds-check the input before copying it into fixed-size memory buffers. This classic buffer overflow condition occurs because the engine allocates memory for host strings without sufficient size validation, allowing attackers to overwrite adjacent memory locations. The flaw falls under the CWE-121 category of stack-based buffer overflow, where the vulnerable code does not properly verify that input data fits within allocated memory boundaries.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it can potentially enable more sophisticated attack vectors. While the primary effect manifests as a system crash or application hang that disrupts legitimate gameplay sessions, the underlying memory corruption could theoretically be exploited to execute arbitrary code on vulnerable systems. However, the specific nature of the buffer overflow in this case limits its exploitation to crash-based attacks rather than privilege escalation or code execution. The vulnerability affects all systems running affected versions of the Unreal Engine, making it particularly dangerous for online gaming platforms and multiplayer server environments where the engine is widely deployed.
Mitigation strategies for CVE-2003-1431 should focus on immediate patch deployment from Epic Games, as the vendor has released updates addressing this specific buffer overflow vulnerability. Organizations operating servers or applications based on the affected Unreal Engine versions must prioritize updating to patched releases, with particular attention to verifying that all game clients and server software are running the latest secure versions. Network administrators should implement monitoring for suspicious Unreal URL patterns and consider implementing input filtering mechanisms that limit host string lengths before they reach the vulnerable parsing code. Additionally, system hardening measures such as stack canaries and address space layout randomization should be considered as supplementary defenses. The vulnerability demonstrates the importance of proper input validation in network protocols and aligns with ATT&CK technique T1203 which covers legitimate program execution through network-based attacks. Organizations should also consider implementing network segmentation and access controls to limit exposure of vulnerable systems to untrusted network traffic containing potentially malicious Unreal URLs.