Nginx UI is a web user interface for the Nginx web server. From 2.0.0 until 2.5.0, Nginx UI accepts the Node.Secret master credential through the node_secret query parameter in HTTP and WebSocket authentication paths instead of requiring the X-Node-Secret header. The credential can consequently appear in access logs, proxy logs, browser history, Referer headers, configuration URLs, and deployment environment data. A party that obtains the secret can bypass normal password, JWT, session, and second-factor checks and obtain persistent administrative API access, including access to configuration and secret material. This issue is fixed in version 2.5.0.
Affected: Go: github.com/0xJacky/Nginx-UI
## 1. Vulnerability Summary
nginx-ui's `Node.Secret` is a master credential that bypasses all JWT/password authentication for the entire API. The application accepts this credential via a **URL query parameter** (`?node_secret=`), causing it to be recorded in plaintext in HTTP access logs, reverse proxy logs, browser history, and HTTP `Referer` headers. Additionally, the official cluster configuration format embeds node secrets directly into URL query strings stored in `app.ini` and environment variables, creating a systemic credential exposure pattern across the entire cluster deployment model.
An attacker who gains read access to any log aggregation system, proxy log, or configuration file can extract the node secret and obtain full, persistent, unauthenticated administrative access to the nginx-ui API — including reading TLS private keys, modifying nginx configurations, and (when chained with Bug #1) achieving OS-level code execution.
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## 2. Root Cause Analysis
### 2.1 Node Secret Accepted as URL Query Parameter
The `getNodeSecret` function reads the credential from the URL query string as a fallback when the `X-Node-Secret` header is absent: [1](#3-0)
This function is called in both `AuthRequired()` and `AuthRequiredWS()` middleware, meaning the query parameter bypass works for **all authenticated HTTP and WebSocket endpoints**: [2](#3-1) [3](#3-2)
The same pattern is repeated in the WebSocket origin checker, which also reads `node_secret` from the URL: [4](…