CVE-2021-30475

Vulnerability

A buffer overflow vulnerability exists in the aom_dsp/noise_model.c file of the libaom library, which implements the AV1 codec. The issue affects all versions of libaom prior to the commit on 2021-03-24 [1]. The overflow occurs in the noise model estimation function, which is reachable when processing specially crafted AV1 bitstreams.

Exploitation

An attacker can exploit this vulnerability by providing a malicious AV1 bitstream to an application using libaom. No authentication is required; the attack vector is network-based if the application processes untrusted input. The exact trigger conditions involve crafted parameters in the noise model data.

Impact

Successful exploitation could lead to memory corruption, potentially resulting in denial of service or remote code execution in the context of the affected application. The Gentoo security advisory classifies this as potentially leading to remote code execution [3].

Mitigation

The issue was fixed in libaom commit 12adc723acf02633595a4d8da8345742729f46c0 [1]. The fix is included in libaom version 3.2.0 and later. Users should upgrade to version 3.2.0 or newer. No known workarounds exist; the Gentoo advisory recommends upgrading to >=media-libs/libaom-3.2.0 [3].