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5.3

urllib3 library allows malicious input to affect Python program behavior

CVE-2019-11236 · published 7 years ago
Summary

A flaw in the urllib3 library for Python can be exploited by an attacker to inject malicious input, potentially causing a program to behave unexpectedly. This could potentially lead to security issues. To mitigate this, update to a fixed version of urllib3.

What to do
  • Update andrey petrov urllib3 to version 1.24.3.
  • Update debian python-urllib3 to version 1.25.6-4.
  • Update rootio-urllib3 to version 1.21.1+root.io.4.
  • Update andrey petrov urllib3 to version 1.21.1+aikido.4.
Affected software
Ecosystem VendorProductAffected versions
pip andrey petrov urllib3 <= 1.24.2
Fix: upgrade to 1.24.3
– python urllib3 <= 1.24.2
cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*
Debian:12 debian python-urllib3 < 1.25.6-4
Fix: upgrade to 1.25.6-4
Debian:13 debian python-urllib3 < 1.25.6-4
Fix: upgrade to 1.25.6-4
Debian:14 debian python-urllib3 < 1.25.6-4
Fix: upgrade to 1.25.6-4
Root:PyPI – rootio-urllib3 < 1.21.1+root.io.4
Fix: upgrade to 1.21.1+root.io.4
Root:PyPI andrey petrov urllib3 < 1.21.1+aikido.4
Fix: upgrade to 1.21.1+aikido.4
Original advisory text
In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter.
In the urllib3 library through 1.24.1 for Python, CRLF injection is possible if the attacker controls the request parameter.
References
Fix within
Internet-facing 60 days
Internal At next upgrade
  • Not known to be exploited
  • Needs hands-on effort to exploit (estimated)
  • Gives an attacker partial control (estimated)
Severity
5.3 Medium
Exploitation
2% chance of attack within 30 days
Type
CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
Timeline
Published15 Apr 2019
Updated4 Nov 2026
First seen6 Mar 2026
Sources
GHSA-r64q-w8jr-g9qp · GHSA
CVE-2019-11236 · NVD
ROOT-APP-PYPI-CVE-2019-11236 · OSV
DEBIAN-CVE-2019-11236 · OSV
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