CVE-2021-23215 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.
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Analysis
by VulDB Data Team • 06/11/2021
The vulnerability identified as CVE-2021-23215 represents a critical integer overflow condition within the DwaCompressor component of the OpenEXR image processing library. This flaw exists in versions prior to 3.0.1 and manifests as a heap-buffer overflow that can be exploited to cause application crashes. The issue stems from improper handling of integer arithmetic during compression operations, specifically when processing image data with the DwaCompressor algorithm. The vulnerability is particularly concerning because OpenEXR is widely used in professional imaging workflows including film production, visual effects, and scientific visualization where applications often process large volumes of image data from untrusted sources.
The technical implementation of this vulnerability involves a scenario where integer overflow occurs during the calculation of buffer sizes or array indices within the compression routine. When an attacker provides specially crafted image data with malicious dimensions or compression parameters, the integer overflow results in a heap buffer overflow condition. This overflow can overwrite adjacent memory regions, potentially leading to arbitrary code execution or denial of service. The vulnerability is classified under CWE-190 as an integer overflow condition and can be mapped to ATT&CK technique T1203 - Exploitation for Client Execution when exploited in application contexts. The DwaCompressor is designed for lossy compression of image data, but the integer overflow occurs during the pre-processing stage where buffer allocations are calculated based on user-provided image parameters.
The operational impact of this vulnerability extends across multiple domains where OpenEXR is deployed, including entertainment industry pipelines, scientific computing environments, and digital asset management systems. Applications compiled with vulnerable versions of OpenEXR are susceptible to crashes when processing malicious image files, which can disrupt production workflows and potentially lead to data loss. The vulnerability is particularly dangerous in automated processing environments where batch operations might be triggered by untrusted input sources, such as user uploads in web applications or file processing systems. Attackers can exploit this flaw by crafting image files with carefully manipulated dimensions that trigger the integer overflow during decompression or compression phases, making it a significant concern for systems handling diverse image inputs.
Mitigation strategies for CVE-2021-23215 primarily involve upgrading to OpenEXR version 3.0.1 or later, which contains the necessary patches to prevent the integer overflow condition. Organizations should also implement input validation measures to sanitize image file parameters before processing, particularly when handling untrusted inputs. Additional protective measures include deploying memory protection mechanisms such as stack canaries, address space layout randomization, and heap metadata protection. System administrators should monitor for exploitation attempts through log analysis and implement network segmentation to limit exposure. The fix addresses the root cause by implementing proper bounds checking and overflow detection in the buffer allocation calculations, ensuring that integer arithmetic results in valid buffer sizes that cannot exceed available heap memory. Security teams should prioritize this vulnerability in their patch management schedules given its potential for remote code execution and the widespread use of OpenEXR in professional imaging environments.