CVE-2017-12939 in Unity Editor
Summary
by MITRE
A Remote Code Execution vulnerability was identified in all Windows versions of Unity Editor, e.g., before 5.3.8p2, 5.4.x before 5.4.5p5, 5.5.x before 5.5.4p3, 5.6.x before 5.6.3p1, and 2017.x before 2017.1.0p4.
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Analysis
by VulDB Data Team • 11/08/2019
The vulnerability CVE-2017-12939 represents a critical remote code execution flaw affecting multiple versions of the Unity game engine editor across all Windows platforms. This vulnerability stems from improper input validation within the Unity Editor's handling of serialized data structures, specifically in the way the engine processes asset files and project configurations. The flaw exists in the serialization mechanism that Unity employs to store and manage project data, creating an exploitable condition where maliciously crafted data can trigger arbitrary code execution when loaded by the vulnerable editor version.
The technical implementation of this vulnerability resides in the Unity Editor's deserialization process, which fails to properly validate the structure and content of serialized data before processing it. When a user opens a specially crafted project file or asset that contains malicious serialized data, the editor's parser does not adequately sanitize the input, allowing an attacker to inject and execute arbitrary code with the privileges of the user running the Unity Editor. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, though it manifests differently in the Unity context through improper deserialization rather than traditional buffer manipulation. The attack vector is particularly concerning as it requires no special privileges beyond being able to convince a user to open a malicious project file, making it a prime target for social engineering attacks.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with complete control over the development environment where the Unity Editor operates. Attackers can leverage this vulnerability to install backdoors, steal source code, modify project assets, or even escalate privileges if the user has elevated system access. The widespread adoption of Unity across game development and other industries means that numerous organizations could be impacted by a single compromised project file, potentially affecting entire development teams. This vulnerability particularly affects the software development lifecycle as it can be exploited during the project development phase, potentially compromising the integrity of source code and development tools. The ATT&CK framework categorizes this as a code injection technique under the T1059.007 sub-technique, with potential for privilege escalation and persistence mechanisms once initial access is achieved.
Mitigation strategies for CVE-2017-12939 primarily focus on immediate version updates to patched releases of the Unity Editor. Organizations should prioritize updating all development environments to versions 5.3.8p2, 5.4.5p5, 5.5.4p3, 5.6.3p1, or 2017.1.0p4 respectively, as these releases contain the necessary patches to address the deserialization vulnerability. Additionally, implementing strict access controls and user education regarding the dangers of opening untrusted project files can significantly reduce the risk of exploitation. Network segmentation and monitoring for unusual file access patterns can also help detect potential exploitation attempts. Security teams should also consider implementing automated patch management systems to ensure all development environments remain up-to-date with the latest security fixes. The vulnerability highlights the importance of secure coding practices in serialization mechanisms and demonstrates how seemingly benign data processing can create critical security risks when proper input validation is not implemented.