CVE-2021-33503

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.

Summary:

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.

Reference Links(if available):

  • https://github.com/advisories/GHSA-q2q7-5pp4-w6pg
  • https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec
  • CVSS Score (if available)

    v2: / MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P

    v3: / HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

    Links to Exploits(if available)