CVE-2017-9115 in OpenEXR
Summary
by MITRE
In OpenEXR 2.2.0, an invalid write of size 2 in the = operator function in half.h could cause the application to crash or execute arbitrary code.
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Analysis
by VulDB Data Team • 12/06/2022
The vulnerability identified as CVE-2017-9115 resides within the OpenEXR library version 2.2.0, specifically targeting the half.h header file's assignment operator implementation. This critical flaw manifests as an invalid write operation of exactly 2 bytes within the = operator function, representing a classic buffer overflow condition that can be exploited to achieve remote code execution or system compromise. The vulnerability stems from inadequate bounds checking during the assignment of half-precision floating-point values, which are commonly used in high dynamic range imaging applications and computer graphics processing pipelines.
The technical implementation of this vulnerability occurs when the assignment operator processes half-precision floating-point data structures, failing to validate the destination buffer boundaries before performing memory writes. This flaw operates at the intersection of memory safety and data type handling, where the 2-byte write operation exceeds the allocated memory space for half-precision values. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, though it can manifest in various memory corruption scenarios depending on the application context and memory layout. The precise nature of the invalid write suggests that the implementation does not properly account for the size requirements of half-precision data types during assignment operations, creating an opportunity for attackers to manipulate memory layout through carefully crafted input data.
The operational impact of CVE-2017-9115 extends across numerous applications that utilize OpenEXR for image processing, particularly in professional graphics environments, film production pipelines, and digital content creation workflows. Systems running affected versions of OpenEXR are vulnerable to both denial of service attacks through application crashes and more severe exploitation scenarios that could lead to arbitrary code execution. The vulnerability is particularly dangerous in environments where OpenEXR is used to process untrusted image files, as attackers could craft malicious EXR files to trigger the buffer overflow during normal file parsing operations. This makes the vulnerability highly relevant to content distribution platforms, image processing services, and any system that accepts and processes EXR image formats from external sources, creating a significant attack surface across creative industries and digital media production environments.
Mitigation strategies for CVE-2017-9115 require immediate patching of affected OpenEXR installations to version 2.2.1 or later, which includes proper bounds checking in the assignment operator implementation. Organizations should implement input validation measures that reject malformed EXR files and employ sandboxing techniques when processing untrusted image content. The vulnerability aligns with ATT&CK technique T1203 by enabling code execution through memory corruption, and T1059 through potential command execution once the exploit is successful. Additionally, system administrators should monitor for exploitation attempts through network traffic analysis and implement intrusion detection systems that can identify malformed EXR file patterns. Regular security assessments of image processing pipelines and comprehensive vulnerability scanning of all OpenEXR-dependent applications are essential for maintaining system integrity and preventing exploitation of this memory corruption vulnerability.