CVE-2025-1943: 
NixOS vulnerability analysis and mitigation

CVE-2025-1943 is a high-impact memory safety vulnerability affecting Firefox 135 and Thunderbird 135, discovered by the Mozilla Fuzzing Team, Andrew McCreight, Sebastian Hengst, and Randell Jesup. The vulnerability was disclosed on March 4, 2025, and has been fixed in Firefox 136 and Thunderbird 136 (Mozilla Advisory, NVD).

The vulnerability encompasses multiple memory safety bugs that showed evidence of memory corruption in Firefox 135 and Thunderbird 135. The issue has been assigned a CVSS 3.1 Base Score of 8.2 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H, indicating a network-exploitable vulnerability with low attack complexity and no required privileges or user interaction (NVD). The vulnerability is classified as CWE-122 (Heap-based Buffer Overflow).

The memory corruption issues could potentially be exploited to run arbitrary code on affected systems. This poses a significant security risk as successful exploitation could lead to unauthorized code execution within the context of the affected applications (Mozilla Advisory).

The vulnerability has been fixed in Firefox 136 and Thunderbird 136. Users are strongly advised to upgrade to these versions to mitigate the risk. For Thunderbird users, it's worth noting that some of these flaws cannot be exploited through email as scripting is disabled when reading mail, but they remain potential risks in browser or browser-like contexts (Mozilla Advisory).