CVE-2025-5204 in Assimp
Summary
by MITRE • 05/27/2025
A vulnerability classified as problematic has been found in Open Asset Import Library Assimp 5.4.3. This affects the function MDLImporter::ParseSkinLump_3DGS_MDL7 of the file assimp/code/AssetLib/MDL/MDLMaterialLoader.cpp. The manipulation leads to out-of-bounds read. Attacking locally is a requirement. The exploit has been disclosed to the public and may be used. The project decided to collect all Fuzzer bugs in a main-issue to address them in the future.
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Analysis
by VulDB Data Team • 05/27/2025
The vulnerability identified as CVE-2025-5204 represents a critical out-of-bounds read flaw within the Open Asset Import Library Assimp version 5.4.3. This security weakness resides in the MDLImporter::ParseSkinLump_3DGS_MDL7 function located in the assimp/code/AssetLib/MDL/MDLMaterialLoader.cpp file, making it a significant concern for software systems that rely on this library for 3D asset processing. The flaw specifically impacts the handling of MDL file formats and demonstrates how improper input validation can lead to memory access violations that compromise system integrity.
The technical implementation of this vulnerability stems from insufficient bounds checking during the parsing of skin data within MDL files, particularly those using the 3DGS_MDL7 format. When the MDLImporter processes malformed or specially crafted MDL files, the ParseSkinLump_3DGS_MDL7 function fails to validate array indices or buffer boundaries before accessing memory locations. This type of flaw falls under CWE-129, which specifically addresses insufficient validation of length of buffers, and represents a classic example of memory safety issues that can lead to information disclosure or potential code execution. The vulnerability requires local attack capabilities, meaning an attacker must have the ability to place malicious files within the system's processing path, though the public disclosure of exploitation techniques significantly increases the risk.
The operational impact of this vulnerability extends beyond simple memory access violations, as it creates potential pathways for information disclosure and system instability. Systems that utilize Assimp for processing 3D content, including game engines, 3D modeling applications, and content management systems, become vulnerable to local attackers who can craft malicious MDL files to trigger the out-of-bounds read condition. This type of vulnerability is particularly concerning in environments where untrusted 3D assets are processed, as it could potentially lead to the exposure of sensitive memory contents or system state information. The vulnerability's classification as a fuzzer-discovered issue indicates that it was likely identified through automated testing methods, highlighting the importance of comprehensive security testing for multimedia processing libraries.
The exploitation of this vulnerability requires local system access and involves the manipulation of MDL files that are processed by applications using the Assimp library. Attackers can craft specially formatted MDL files containing malformed skin data that will trigger the out-of-bounds read when the ParseSkinLump_3DGS_MDL7 function attempts to parse the data structure. This exploitation technique aligns with ATT&CK tactic T1059, which covers execution through command and scripting interpreters, as the vulnerability enables local code execution through the processing of malicious assets. The fact that the exploit has been disclosed publicly means that threat actors can readily develop and deploy attacks against systems using vulnerable versions of Assimp. Organizations should consider the implications of this vulnerability in their software supply chains, particularly in applications that handle third-party 3D content, as the vulnerability could be exploited to gain unauthorized access to system resources or extract sensitive information from memory.
Mitigation strategies for CVE-2025-5204 should focus on immediate version updates to Assimp 5.4.4 or later, which contain the necessary patches to address the out-of-bounds read condition. System administrators should implement comprehensive patch management procedures to ensure all applications utilizing Assimp are updated promptly. Additionally, organizations should consider implementing input validation controls and sandboxing mechanisms for processing 3D assets, particularly those from untrusted sources. The project's decision to consolidate all fuzzer bugs in a main issue demonstrates a proactive approach to vulnerability management, though immediate remediation remains essential. Security teams should also consider monitoring for exploitation attempts through network intrusion detection systems, as the vulnerability's public disclosure increases the likelihood of active exploitation attempts in the wild.