CVE-2021-33503

HIGH

urllib3 <1.26.5 - DoS

Title source: llm
STIX 2.1

Description

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.

References (6)

Core 6
Core References
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202107-36
Patch, Third Party Advisory x_refsource_misc
https://www.oracle.com/security-alerts/cpuoct2021.html
Third Party Advisory x_refsource_confirm
https://github.com/advisories/GHSA-q2q7-5pp4-w6pg

Scores

CVSS v3 7.5
EPSS 0.0086
EPSS Percentile 75.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-400
Status published
Products (9)
fedoraproject/fedora 33
fedoraproject/fedora 34
oracle/enterprise_manager_ops_center 12.4.0.0
oracle/instantis_enterprisetrack 17.1
oracle/instantis_enterprisetrack 17.2
oracle/instantis_enterprisetrack 17.3
oracle/zfs_storage_appliance_kit 8.8
pypi/urllib3 1.25.4 - 1.26.5PyPI
python/urllib3 1.25.4 - 1.26.5
Published Jun 29, 2021
Tracked Since Feb 18, 2026