CVE-2023-37573: 
NixOS vulnerability analysis and mitigation

Multiple use-after-free vulnerabilities exist in the VCD get_vartoken realloc functionality of GTKWave 3.3.115. A specially crafted .vcd file can lead to arbitrary code execution. A victim would need to open a malicious file to trigger these vulnerabilities. This vulnerability specifically concerns the use-after-free when triggered via the GUI's recoder (default) VCD parsing code (Talos, NVD).

The vulnerability is classified as CWE-416 (Use After Free) with a CVSS v3.1 Base Score of 7.8 HIGH (Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H). The issue occurs in the VCD get_vartoken realloc functionality where a buffer reallocation may move memory to a different location, causing varsplit to point to freed memory. This can lead to out-of-bounds writes through controlled buffer lengths and arbitrary code execution (Talos).

The vulnerability can lead to arbitrary code execution when a victim opens a malicious .vcd file. The high CVSS score indicates potential severe impacts on confidentiality, integrity, and availability of the affected system (Talos).

The vulnerability has been fixed in GTKWave version 3.3.118. Users are recommended to upgrade to this version or later. The fix has been backported to various Linux distributions, including Debian 10 (buster) as version 3.3.98+really3.3.118-0+deb10u1 (Debian LTS).