Nginx-Ui · Nginx-Ui · CVE-2026-33028
**Name of the Vulnerable Software and Affected Versions**
Nginx UI versions prior to 2.3.4
**Description**
Nginx UI is susceptible to a race condition due to the absence of synchronization mechanisms and non-atomic file writes. Concurrent requests can severely corrupt the primary configuration file (`app.ini`), leading to a persistent Denial of Service (DoS). This corruption also introduces a potential, though non-deterministic, path to Remote Code Execution (RCE) through configuration cross-contamination. The issue arises because the settings update pipeline lacks synchronization primitives, causing memory and file corruption when multiple requests are processed simultaneously. Specifically, the `ProtectedFill()` function modifies shared global singleton pointers without thread safety, and the underlying library performs direct, concurrent overwrites to the `app.ini` file. This can result in incomplete or truncated configuration keys, leading to application failure or a complete service collapse. The vulnerability can be triggered by sending concurrent `POST /api/settings` requests, potentially corrupting the `app.ini` file and causing the service to redirect to the installation page or become unresponsive.
**Recommendations**
Versions prior to 2.3.4 should be updated to version 2.3.4 or later.