An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.
CVE-2021-33503 - High Severity Vulnerability
HTTP library with thread-safe connection pooling, file post, and more.
Library home page: https://files.pythonhosted.org/packages/23/fc/8a49991f7905261f9ca9df5aa9b58363c3c821ce3e7f671895442b7100f2/urllib3-1.26.3-py2.py3-none-any.whl
Path to dependency file: /client/python
Path to vulnerable library: /client/python
Dependency Hierarchy: - requests-2.25.1-py2.py3-none-any.whl (Root Library) - :x: **urllib3-1.26.3-py2.py3-none-any.whl** (Vulnerable Library)
Found in base branch: master
An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.
Publish Date: 2021-06-29
URL: CVE-2021-33503
Base Score Metrics: - Exploitability Metrics: - Attack Vector: Network - Attack Complexity: Low - Privileges Required: None - User Interaction: None - Scope: Unchanged - Impact Metrics: - Confidentiality Impact: None - Integrity Impact: None - Availability Impact: High
For more information on CVSS3 Scores, click here.Type: Upgrade version
Origin: https://github.com/urllib3/urllib3/security/advisories/GHSA-q2q7-5pp4-w6pg
Release Date: 2021-06-29
Fix Resolution (urllib3): 1.26.5
Direct dependency fix Resolution (requests): 2.26.0
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