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
Vulnerable Library - urllib3-1.24.2-py2.py3-none-any.whl
HTTP library with thread-safe connection pooling, file post, and more.
Library home page: https://files.pythonhosted.org/packages/df/1c/59cca3abf96f991f2ec3131a4ffe72ae3d9ea1f5894abe8a9c5e3c77cfee/urllib3-1.24.2-py2.py3-none-any.whl
Path to dependency file: /docs/requirements.txt
Path to vulnerable library: /docs/requirements.txt
Dependency Hierarchy: - :x: **urllib3-1.24.2-py2.py3-none-any.whl** (Vulnerable Library)
Found in HEAD commit: 8df0c9edde054463776fa58e88036ee2a783a41f
Found in base branch: master
Vulnerability Details
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
CVSS 3 Score Details (7.5)
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.Suggested Fix
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
:rescue_worker_helmet: Automatic Remediation is available for this issue