CVE-2020-36133 in AOM
Summary
by MITRE • 12/03/2021
AOM v2.0.1 was discovered to contain a global buffer overflow via the component av1/encoder/partition_search.h.
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Analysis
by VulDB Data Team • 12/08/2021
The vulnerability identified as CVE-2020-36133 represents a critical buffer overflow condition within the AOM (AOMedia) v2.0.1 video encoding library, specifically within the av1/encoder/partition_search.h component. This flaw exists in the AV1 video codec implementation used by various multimedia applications and streaming platforms. The buffer overflow occurs during the partition search phase of video encoding operations where the software fails to properly validate input data lengths before writing to memory buffers. The vulnerability stems from inadequate bounds checking mechanisms that allow maliciously crafted input data to exceed allocated buffer boundaries, potentially leading to arbitrary code execution or system instability.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The flaw manifests when the partition search algorithm processes encoded video frames without sufficient validation of the data structures it manipulates, particularly in scenarios involving complex video encoding operations with varying partition sizes. Attackers could exploit this vulnerability by feeding specially crafted video streams that trigger the buffer overflow condition during the encoding process. The operational impact extends beyond simple crashes to potentially enable remote code execution, making it particularly dangerous for applications that process untrusted video content from external sources.
This vulnerability affects systems that utilize the AOM library for AV1 video encoding, including web browsers, media players, streaming platforms, and content creation software. The attack surface is broad given that AV1 is increasingly adopted across various platforms for its superior compression efficiency. The exploitation of this vulnerability could allow adversaries to execute arbitrary code with the privileges of the affected application, potentially leading to complete system compromise. Organizations using affected software may experience denial of service conditions or unauthorized access to sensitive data, particularly in environments where video processing applications handle untrusted input from multiple sources. The vulnerability's impact is amplified by the fact that AV1 encoding is commonly used in real-time streaming applications where input validation may be minimal or deferred until processing occurs.
Mitigation strategies for CVE-2020-36133 should prioritize immediate patching of affected AOM library versions to the latest stable release that contains the buffer overflow fix. Organizations should implement input validation controls at application boundaries to sanitize video data before processing, particularly for applications that handle untrusted content. Network segmentation and access controls should be reinforced to limit potential attack vectors, while monitoring systems should be deployed to detect anomalous video processing patterns that might indicate exploitation attempts. The implementation of address space layout randomization and stack canaries can provide additional defense-in-depth measures. Regular security assessments of multimedia processing pipelines are essential to identify similar vulnerabilities in other codec implementations, while adherence to secure coding practices such as those outlined in the CERT Secure Coding Standards should be maintained throughout the software development lifecycle to prevent future buffer overflow conditions.