CVE-2021-0691: 
NixOS vulnerability analysis and mitigation

CVE-2021-0691 is a security vulnerability in the SELinux policy configured in systemapp.te of Android 11. The vulnerability was disclosed in September 2021 and affects Android systems. The issue allows systemapp to gain code execution in other processes due to an overly-permissive SELinux policy (Android Bulletin).

The vulnerability stems from an overly-permissive SELinux policy configuration in system_app.te that could lead to local escalation of privilege. The severity is rated as MEDIUM with a CVSS v3.1 base score of 6.7 (Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H). The vulnerability is classified under CWE-269 (Improper Privilege Management) (NVD).

If exploited, this vulnerability could allow an attacker with system_app privileges to execute code in other processes, leading to local escalation of privilege with System execution privileges. The vulnerability affects confidentiality, integrity, and availability of the system (NVD).

The vulnerability was addressed in the Android Security Bulletin of September 2021. Users should update their Android devices to the latest available security patch level to mitigate this vulnerability (Android Bulletin).