CVE-2021-45266 in GPAC
Summary
by MITRE • 12/22/2021
A null pointer dereference vulnerability exists in gpac 1.1.0 via the lsr_read_anim_values_ex function, which causes a segmentation fault and application crash.
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Analysis
by VulDB Data Team • 12/25/2021
The vulnerability identified as CVE-2021-45266 represents a critical null pointer dereference flaw within the gpac multimedia framework version 1.1.0. This issue specifically manifests within the lsr_read_anim_values_ex function, which is responsible for processing animation values in lsr files. The gpac library serves as a comprehensive multimedia framework that supports various codecs and file formats including mp4, aac, and avc, making it a widely used component in multimedia applications and streaming services. The vulnerability arises when the function attempts to dereference a null pointer during the processing of malformed animation data, leading to immediate system termination through segmentation fault.
From a technical perspective, this null pointer dereference vulnerability falls under the CWE-476 category of NULL Pointer Dereference, which is classified as a common weakness in software security practices. The lsr_read_anim_values_ex function fails to properly validate input parameters before attempting to access memory locations, creating an exploitable condition where maliciously crafted lsr files can trigger the vulnerability. The function's improper handling of animation value parsing creates a scenario where a null pointer is passed to subsequent operations, resulting in an immediate segmentation fault that terminates the application process. This type of vulnerability is particularly dangerous in multimedia processing applications where users may unknowingly open maliciously crafted files, as the crash occurs during normal file processing operations rather than requiring special exploitation techniques.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged for denial of service attacks against systems that rely on gpac for multimedia processing. When exploited, the segmentation fault causes the application to terminate abruptly, potentially leading to data loss or service disruption in environments where gpac is integrated into larger multimedia workflows. The vulnerability affects systems running gpac 1.1.0 and earlier versions, with the potential for cascading failures in applications that depend on this library for multimedia content processing. This issue is particularly concerning in streaming environments, content delivery networks, and multimedia editing applications where the gpac library is extensively used.
Mitigation strategies for CVE-2021-45266 should focus on immediate patching of the gpac library to version 1.1.1 or later, where the null pointer dereference has been addressed through proper input validation. System administrators should implement strict file validation procedures for lsr files, particularly in environments where users can upload or process external multimedia content. The implementation of sandboxing mechanisms and input sanitization can provide additional protection layers against exploitation attempts. Security monitoring should be enhanced to detect unusual application termination patterns that may indicate exploitation attempts. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems running vulnerable gpac versions. The ATT&CK framework categorizes this vulnerability under T1499.004 for Network Denial of Service, as the exploitation can lead to service disruption through application crashes. Regular security audits and vulnerability assessments should be conducted to identify similar issues in other multimedia libraries and frameworks that may be susceptible to similar null pointer dereference conditions.