Executive brief
Label Studio is an open-source data labeling platform used for machine learning workflows. Its default deployment uses Nginx with a misconfigured static file serving rule that allows attackers to bypass access restrictions and read sensitive application files like Django configuration and secret keys. An attacker with network access can exploit this without authentication to steal secrets used for session management and potentially take over user accounts or access the application database.
Technical details
The vulnerability is a path traversal flaw in the Nginx configuration file (deploy/default.conf) affecting the /static location directive. The root cause is a missing trailing slash in the location pattern: `location /static` instead of the secure `location /static/`. This misconfiguration allows Nginx to match requests like `/static../settings/label_studio.py`, which traverses to the parent directory and accesses files outside the intended static asset directory. The vulnerability requires no authentication or user interaction—any network-accessible Label Studio instance using the default Nginx deployment is exposed. Attackers can read arbitrary files in the /label_studio/core/ directory, including Django settings files containing secret keys, database credentials, and other sensitive configuration. The issue affects Label Studio versions ≤ 1.7.1 and was patched in version 1.7.2.
Affected products
- HumanSignal Label Studio <= 1.7.1
Timeline
- 2023-03-24: disclosed: Vulnerability disclosed via GitHub Advisory GHSA-cpmr-mw4j-99r7
- 2023-03-24: patched: Fixed in Label Studio version 1.7.2