CVE-2025-20881: 
NixOS vulnerability analysis and mitigation

CVE-2025-20881 is a high-severity vulnerability discovered in Samsung's libsthmbc.so library. The vulnerability was first reported on February 2, 2024, and publicly disclosed in January 2025. It affects Samsung Android devices running versions 12, 13, and 14. The vulnerability is characterized as an out-of-bounds write issue in accessing buffer storing the decoded video frames (Samsung Mobile, NVD).

The vulnerability is classified as an out-of-bounds write (CWE-787) vulnerability. It received a CVSS v3.1 base score of 7.8 (High) from NIST with the vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, while Samsung Mobile assessed it with a score of 7.0 (High) with the vector string CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. The vulnerability specifically affects the buffer handling mechanism in the libsthmbc.so library when accessing decoded video frames (NVD).

If exploited, the vulnerability allows local attackers to execute arbitrary code with privilege. The successful exploitation requires user interaction, but could lead to complete compromise of the affected system's confidentiality, integrity, and availability (Samsung Mobile).

Samsung has addressed this vulnerability in their January 2025 Security Maintenance Release (SMR Jan-2025 Release 1). The patch implements proper input validation to prevent out-of-bounds write operations. Users are advised to update their devices to the latest security patch level (Samsung Mobile).