PT-2026-53646 · Pypi · Zrok

Published

2026-06-29

·

Updated

2026-06-29

CVSS v4.0

9.9

Critical

VectorAV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:L

Summary

Alice exposes a Python SDK ProxyShare with a fixed target URL. Bob sends a request to the share with an absolute URL in the path. The Flask handler passes that path to urllib.parse.urljoin, which replaces Alice's configured target host with Bob's host and returns the server-side response to Bob.

Details

The Python SDK proxy route accepts every path under the share:
python
@app.route('/', defaults={'path': ''}, methods=['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'OPTIONS'])
@app.route('/<path:path>', methods=['GET', 'POST', 'PUT', 'DELETE', 'PATCH', 'OPTIONS'])
def proxy(path):
It constructs the outbound URL with urljoin and then sends the request:
python
url = urllib.parse.urljoin(self.target, path)
resp = requests.request(
  method=request.method,
  url=url,
  headers={key: value for (key, value) in request.headers
       if key.lower() not in HOP BY HOP HEADERS},
  data=request.get data(),
  cookies=request.cookies,
  allow redirects=False,
  stream=True,
  verify=self.verify ssl
)
When path is [http://127.0.0.1:19190/metadata](http://127.0.0.1:19190/metadata%60), urljoin(self.target, path) returns [http://127.0.0.1:19190/metadata](http://127.0.0.1:19190/metadata%60). The proxy sends the request to Bob's chosen URL rather than Alice's target.

Fix

Found an issue in the description? Have something to add? Feel free to write us 👾
dbugs@ptsecurity.com

Related Identifiers

PYSEC-2026-577

Affected Products

Zrok