2026-03-24 15:16:14
GitHub_M
PUBLISHED
Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper enables `nodeIntegration` in the main BrowserWindow and does not restrict same-window navigations. An attacker who can place a link in user-generated content (task descriptions, comments, project descriptions) can cause the BrowserWindow to navigate to an attacker-controlled origin, where JavaScript executes with full Node.js access, resulting in arbitrary code execution on the victims machine. Version 2.2.0 patches the issue. ## Root cause Two misconfigurations combine to create this vulnerability: 1. **`nodeIntegration: true`** is set in `BrowserWindow` web preferences (`desktop/main.js:14-16`), giving any page loaded in the renderer full access to Node.js APIs (`require`, `child_process`, `fs`, etc.). 2. **No `will-navigate` or `will-redirect` handler** is registered on the `webContents`. The existing `setWindowOpenHandler` (`desktop/main.js:19-23`) only intercepts `window.open()` calls (new-window requests). It does **not** intercept same-window navigations triggered by: - `` links (without `target="_blank"`) - `window.location` assignments - HTTP redirects - `` tags ## Attack scenario 1. The attacker is a normal user on the same Vikunja instance (e.g., a member of a shared project). 2. The attacker creates or edits a project description or task description containing a standard HTML link, e.g.: `Click here for the updated design spec` 3. The Vikunja frontend renders this link. DOMPurify sanitization correctly allows it -- it is a legitimate anchor tag, not a script injection. Render path example: `frontend/src/views/project/ProjectInfo.vue` uses `v-html` with DOMPurify-sanitized output. 4. The victim uses Vikunja Desktop and clicks the link. 5. Because no `will-navigate` handler exists, the BrowserWindow navigates to `https://evil.example/exploit` in the same renderer process. 6. The attackers page now executes in a context with `nodeIntegration: true` and runs: `require(child_process).exec(id > /tmp/pwned);` 7. Arbitrary commands execute as the victims OS user. ## Impact Full remote code execution on the victims desktop. The attacker can read/write arbitrary files, execute arbitrary commands, install malware or backdoors, and exfiltrate credentials and sensitive data. No XSS vulnerability is required -- a normal, sanitizer-approved hyperlink is sufficient. ## Proof of concept 1. Set up a Vikunja instance with two users sharing a project. 2. As the attacker user, edit a project description to include: `Meeting notes` 3. Host poc.html with: `` 4. As the victim, open the project in Vikunja Desktop and click the link. 5. calc.exe (or any other command) executes on the victims machine. ## Credits This vulnerability was found using [GitHub Security Lab Taskflows](https://github.com/GitHubSecurityLab/seclab-taskflows).