CVE-2021-44918: 
NixOS vulnerability analysis and mitigation

A Null Pointer Dereference vulnerability was discovered in GPAC version 1.1.0 affecting the gfnodeget_field function. The vulnerability was reported on December 10, 2021, and assigned identifier CVE-2021-44918. This security flaw affects the GPAC multimedia framework, specifically its core functionality for handling node fields (GitHub Issue).

The vulnerability manifests as a null pointer dereference in the gfnodegetfield function, which can be triggered when processing certain media files. When exploited, the vulnerability causes the application to attempt to access an invalid memory location, leading to a segmentation fault. The issue was confirmed through debug analysis showing the crash occurring at address 0x00007ffff784acf0 in the gfnodegetfield function (GitHub Issue).

When triggered, the vulnerability results in a segmentation fault that causes the application to crash, leading to a denial of service condition. This can affect the stability and availability of applications using the GPAC framework (GitHub Issue).

The vulnerability was addressed in subsequent versions of GPAC. Users are recommended to upgrade to a version newer than 1.1.0. For systems where upgrading is not immediately possible, avoiding the processing of untrusted input files with the affected functionality can serve as a temporary mitigation (Debian Security Tracker).