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.
Published: 2021-06-29
CVSS: 7.5
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Download Exploit for CVE-2021-33503 here:
Tip: Download official Tor Browser at https://www.torproject.org/download/ to access .onion links.
https://augustaverburg.nl/exploit-665-cve-2025-47827/
https://augustaverburg.nl/exploit-412-cve-2025-64504/
https://augustaverburg.nl/exploit-839-cve-2024-24791/
https://augustaverburg.nl/exploit-563-cve-2013-2251/
https://augustaverburg.nl/exploit-595-cve-2023-6345/