VULNERABILITY INTELLIGENCE

CVE-2021-3733

CVSS score6.5 MEDIUM
EPSS probability4.80%
CISA KEVNot currently listed
Published2022-03-10
Last modified2026-10-14
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

There's a flaw in urllib's AbstractBasicAuthHandler class. An attacker who controls a malicious HTTP server that an HTTP client (such as web browser) connects to, could trigger a Regular Expression Denial of Service (ReDOS) during an authentication request with a specially crafted payload that is sent by the server to the client. The greatest threat that this flaw poses is to application availability.

Weakness classification

  • secalert@redhat.com: CWE-400
  • nvd@nist.gov: CWE-400

Primary references