CVE-2021-33503 - CVE House
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Status published High CVE-2021-33503

An issue was discovered in urllib3 before 1.26.5. When provided...

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

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Affected Vendor

Affected Software

urllib3, fedora, enterprise manager ops center, instantis enterprisetrack, zfs storage appliance kit
Vulnerable Versions:
1.25.4, 33, 34, 12.4.0.0, 17.1, 17.2, 17.3, 8.8

Timeline

Official Publish: June 29th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.