CVE-2025-55763: 
Linux Debian vulnerability analysis and mitigation

Buffer Overflow vulnerability (CVE-2025-55763) affects CivetWeb versions 1.14 through 1.16 (latest). The vulnerability was discovered and disclosed on August 29, 2025, affecting the URI parser component of the CivetWeb embedded web server. This security flaw impacts all installations of CivetWeb from version 1.14 up to and including the latest 1.16 release (NVD).

The vulnerability is a heap buffer overflow in the URI parser component that processes HTTP requests. The issue occurs during request processing when handling directory URI redirections in the handle_request() function. The vulnerability stems from unsafe usage of strcat operations that can lead to buffer overflow conditions. The CVSS v3.1 base score is 7.5 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, indicating a high severity issue that can be exploited remotely without requiring privileges or user interaction (NVD).

When successfully exploited, this vulnerability allows an attacker to corrupt heap memory through crafted HTTP requests. The primary impacts include potential denial of service conditions or arbitrary code execution on affected systems. The vulnerability affects the core request processing functionality, making it a critical security concern for all deployments (NVD).

A fix has been proposed that replaces unsafe strcat usage with strncat to ensure proper buffer size validation. The patch has been submitted as a pull request to the CivetWeb repository and includes full unit test verification. Until the patch is officially released, users are advised to monitor the CivetWeb repository for updates (Github PR).