CVE-2021-26260 in OpenEXR
Summary
by MITRE • 06/08/2021
An integer overflow leading to a heap-buffer overflow was found in the DwaCompressor of OpenEXR in versions before 3.0.1. An attacker could use this flaw to crash an application compiled with OpenEXR. This is a different flaw from CVE-2021-23215.
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Analysis
by VulDB Data Team • 06/11/2021
The vulnerability CVE-2021-26260 represents a critical integer overflow condition within the DwaCompressor component of OpenEXR software versions prior to 3.0.1. This flaw exists in the handling of compressed image data structures where insufficient input validation leads to improper arithmetic operations that can cause integer overflow conditions. The vulnerability specifically affects the decompression process of OpenEXR files, which are widely used in professional visual effects and animation production environments where image data integrity is paramount. The flaw demonstrates characteristics consistent with CWE-190, which describes integer overflow conditions that can lead to buffer overflows and arbitrary code execution scenarios. Attackers exploiting this vulnerability can craft malicious OpenEXR files that trigger the overflow during decompression, potentially causing application crashes or more severe system instability. The issue is particularly concerning in environments where OpenEXR files are processed automatically or through automated workflows, as these scenarios can be exploited without user interaction.
The technical implementation of this vulnerability stems from improper bounds checking within the DwaCompressor's memory allocation routines. When processing compressed data streams, the software fails to validate input parameters that determine buffer sizes, leading to situations where integer arithmetic operations exceed maximum representable values. This overflow condition results in heap-based buffer overflows that can overwrite adjacent memory regions, causing unpredictable application behavior including crashes, data corruption, or potential code execution. The vulnerability is classified under ATT&CK technique T1203, which involves exploiting input validation flaws to cause application instability or crashes. The flaw specifically manifests when the decompression algorithm attempts to allocate memory blocks based on corrupted or manipulated header values from the OpenEXR file format, creating a scenario where the intended buffer size calculation produces an unexpectedly large value that exceeds available heap space.
The operational impact of CVE-2021-26260 extends beyond simple application crashes to potentially compromise entire production pipelines in visual effects and animation studios. Professional environments relying on OpenEXR for high-end rendering workflows face significant risks when this vulnerability is exploited, as it can lead to complete render failures or data loss during critical production phases. The vulnerability affects applications compiled with OpenEXR libraries, making it particularly dangerous in automated systems where file processing occurs without human oversight. Security teams responsible for protecting creative technology infrastructure must consider this flaw as part of their threat modeling, especially in environments where external file inputs are processed. The vulnerability's impact is amplified by the fact that OpenEXR files are commonly exchanged between different software applications and studios, making it possible for attackers to deliver malicious payloads through legitimate file transfer mechanisms.
Mitigation strategies for CVE-2021-26260 require immediate software updates to OpenEXR version 3.0.1 or later, which includes proper input validation and integer overflow protection mechanisms. Organizations should implement comprehensive patch management procedures to ensure all systems processing OpenEXR files receive the necessary security updates. Additional protective measures include implementing file validation routines that check for suspicious header values before processing, deploying network-based intrusion detection systems that can identify malicious OpenEXR file patterns, and establishing secure file handling protocols that prevent automatic processing of untrusted input files. Security monitoring should focus on detecting unusual application crash patterns or memory allocation errors that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of proper input validation in multimedia processing libraries, where buffer overflows can have cascading effects on entire production workflows. Organizations should also consider implementing sandboxed environments for processing untrusted OpenEXR files and establishing incident response procedures specifically tailored to handle multimedia file format vulnerabilities.