PyLoad's download engine accepts arbitrary URLs without validation, enabling Server-Side Request Forgery (SSRF) attacks. An authenticated attacker can exploit this to access internal network services and exfiltrate cloud provider metadata. On DigitalOcean droplets, this exposes sensitive infrastructure data including droplet ID, network configuration, region, authentication keys, and SSH keys configured in user-data/cloud-init.
The vulnerability exists in PyLoad's download package functionality (/api/addPackage endpoint), which directly passes user-supplied URLs to the download engine without validating the destination. The affected code in src/pyload/webui/app/blueprints/api_blueprint.py:
@bp.route("/addPackage", methods=["POST"], endpoint="add_package")
@login_required
def add_package():
name = flask.request.form["add_name"]
links = flask.request.form["add_links"].split("\n")
# ... validation omitted ...
api.add_package(name, links, dest) # No URL validation
The download engine in src/pyload/core/managers/download.py accepts any URL scheme and initiates HTTP requests to arbitrary destinations, including internal network addresses and cloud metadata endpoints.
Live Demo Instance: http://143.244.141.81:8000
Credentials: pyload / pyload
http://169.254.169.254/metadata/v1.json
The downloaded v1.json file contains sensitive cloud infrastructure data:
Vulnerability Type: Server-Side Request Forgery (SSRF)
CVSS Score: 7.7 - 9.1 (High to Critical, depending on cloud deployment)
Implement URL validation in the download engine: