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How the CVE Works
The vulnerability occurs because urllib3 improperly handles redirects when configured via the `PoolManager` retries parameter. Despite setting retries=0, retries=Retry(redirect=0), or retries=False, the library fails to disable redirects. This allows unintended HTTP redirects, enabling Server-Side Request Forgery (SSRF) or open-redirect attacks. Applications attempting to mitigate SSRF by disabling redirects at the `PoolManager` level remain vulnerable due to this misconfiguration.
DailyCVE Form
Platform: urllib3
Version: <2.0.0
Vulnerability: Improper Redirect Handling
Severity: Critical
Date: 2023-10-11
Prediction: Patch by Q4 2023
What Undercode Say
import urllib3
http = urllib3.PoolManager(retries=0) Flawed redirect disable
resp = http.request("GET", "https://evil.com/redirect") Still follows redirects
How Exploit
1. Attacker crafts malicious URL.
2. Server processes redirect, exposing internal services.
3. SSRF leads to data exfiltration.
Protection from this CVE
- Upgrade to urllib3 >=2.0.0.
- Disable redirects per-request (
redirect=False). - Validate URLs pre-request.
Impact
- SSRF exploitation.
- Internal network exposure.
- Bypassed security controls.
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
