CVE-2023-38652: 
NixOS vulnerability analysis and mitigation

Multiple integer overflow vulnerabilities exist in the VZT vzt_rd_block_vch_decode dict parsing functionality of GTKWave 3.3.115. A specially crafted .vzt file can lead to memory corruption. A victim would need to open a malicious file to trigger these vulnerabilities. This vulnerability specifically concerns the integer overflow when num_time_ticks is not zero (Talos Report).

The vulnerability exists in the VZT vzt_rd_block_vch_decode dict parsing functionality. When processing .vzt files, if b->rle is set (when start_time is bigger than end_time in the input file), a val_dict allocation is performed with a size calculated as (num_sections * num_dict_entries) * sizeof(vztint32_t). This calculation can overflow, leading to an overly small allocation of the buffer. The vulnerability has 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) according to NVD, while Talos rates it at 7.0 HIGH (Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H) (NVD, Talos Report).

The vulnerability can lead to memory corruption when a specially crafted .vzt file is processed. Due to the multi-threaded nature of GTKWave and the decompression code, writing out-of-bounds in the decompression thread may lead to corrupting a thread nearby, potentially resulting in arbitrary code execution (Talos Report).

The vulnerability has been fixed in GTKWave version 3.3.118. Various Linux distributions have also released security updates to address this vulnerability, including Debian which has released updates for multiple versions (Debian LTS, Debian Security).