CVE-2025-8854 in bullet3
Summary
by MITRE • 08/11/2025
Stack-based buffer overflow in LoadOFF in bulletphysics bullet3 before 3.26 on all platforms allows remote attackers to execute arbitrary code via a crafted OFF file with an overlong initial token processed by the VHACD test utility or invoked indirectly through PyBullet's vhacd function.
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Analysis
by VulDB Data Team • 12/08/2025
The vulnerability identified as CVE-2025-8854 represents a critical stack-based buffer overflow within the LoadOFF function of the bulletphysics bullet3 library version 3.25 and earlier. This flaw exists across all supported platforms and stems from inadequate input validation when processing OFF (Object File Format) files. The vulnerability specifically manifests when the VHACD (Volumetric Hierarchical Approximate Convex Decomposition) test utility encounters a crafted OFF file containing an overlong initial token. The buffer overflow occurs during the parsing of the file header, where the software fails to properly bounds-check the token length before copying it to a fixed-size stack buffer. This vulnerability is particularly concerning as it can be exploited remotely through the processing of malicious OFF files, making it a significant threat to applications that utilize the bullet physics engine for 3D graphics and physics simulation. The issue is not limited to direct exploitation of the VHACD utility but also extends to indirect exploitation through PyBullet's vhacd function, which is widely used in Python-based physics simulations and game development environments.
The technical implementation of this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which occurs when a program writes data to a buffer located on the stack without proper bounds checking. The flaw exploits the fundamental weakness in memory management where the software assumes that input data will not exceed predetermined limits, leading to memory corruption that can be leveraged by attackers to overwrite adjacent stack memory locations. The VHACD utility's handling of the OFF file format creates a specific attack surface where the initial token parsing process fails to validate the maximum allowable token length, allowing an attacker to craft input that exceeds the allocated buffer size. This type of vulnerability is particularly dangerous because it can be triggered during normal file processing operations, making it difficult to detect and prevent through standard security measures. The stack-based nature of the overflow means that the attacker can potentially overwrite return addresses, function pointers, or other critical stack data, enabling arbitrary code execution with the privileges of the affected process.
The operational impact of this vulnerability extends across multiple domains where bullet physics engine is utilized, including game development environments, 3D modeling applications, and scientific computing platforms that rely on accurate physics simulation. Applications using PyBullet's vhacd function are particularly at risk as this function provides a direct interface to the vulnerable code path, making it accessible to attackers who can craft malicious OFF files for processing. The remote exploitation capability means that attackers can deliver malicious files through various vectors including web applications, file sharing services, or email attachments, without requiring user interaction beyond the normal file processing workflow. This vulnerability can lead to complete system compromise, data exfiltration, or denial of service conditions depending on how the affected applications handle the memory corruption. Security professionals must consider the widespread adoption of bullet physics libraries in both commercial and open source projects, making this vulnerability potentially exploitable across a broad range of systems and applications. The vulnerability's presence in PyBullet specifically impacts Python-based applications that perform 3D mesh processing, which includes computer graphics applications, simulation software, and machine learning platforms that utilize physics-based rendering.
Mitigation strategies for CVE-2025-8854 must address both the immediate vulnerability and broader security considerations for systems utilizing bullet physics libraries. The primary recommendation is to upgrade to bulletphysics bullet3 version 3.26 or later, which contains the necessary patches to prevent the buffer overflow condition. Organizations should implement strict input validation measures for all OFF file processing, including length checks on initial tokens and implementation of safe string handling practices. The security community should also consider implementing application sandboxing or containerization for applications that process external 3D files, limiting the potential impact of successful exploitation attempts. Network-level defenses such as content filtering and file type validation can help prevent malicious OFF files from reaching vulnerable applications, while regular security audits of applications using bullet physics libraries can help identify potential exposure points. Additionally, developers should adopt secure coding practices that emphasize bounds checking and memory safety, particularly when implementing file parsing functions that handle external input. The vulnerability serves as a reminder of the importance of comprehensive input validation in security-critical code sections and the need for regular security assessments of third-party libraries. Organizations should also consider implementing automated vulnerability scanning tools that can detect the presence of vulnerable library versions and alert administrators to potential exposure risks.