VULNERABILITY INTELLIGENCE
CVE-2021-33503
CVSS score7.5 HIGH
EPSS probability3.27%
CISA KEVNot currently listed
Published2021-06-29
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Weakness classification
- CWE-400: Uncontrolled Resource Consumption
Primary references
- cve@mitre.org — Third Party Advisory
- cve@mitre.org — Patch, Third Party Advisory
- cve@mitre.org
- cve@mitre.org
- cve@mitre.org — Third Party Advisory
- cve@mitre.org — Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory