OAuthLib vulnerable DoS when attacker provides malicious IPV6 URI

Summary

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. In OAuthLib versions 3.1.1 until 3.2.1, an attacker providing malicious redirect uri can cause denial of service. An attacker can also leverage usage of `uri_validate` functions depending where it is used. OAuthLib applications using OAuth2.0 provider support or use directly `uri_validate` are affected by this issue. Version 3.2.1 contains a patch. There are no known workarounds.

Timeline

1. Sep 9, 2022, 12:00 AM UTCCVE published
2. Apr 22, 2025, 3:44 PM UTCCISA SSVC assessment

   Exploitation: poc · Automatable: no · Technical impact: partial

3. Apr 22, 2025, 5:22 PM UTCRecord last updated

Affected versions

• oauthlib oauthlib

  From 3.1.1 · fixed in 3.2.1

• oauthlibPyPI

  From 3.1.1 · fixed in 3.2.2

• oauthlibPyPI

  From 3.1.1 · fixed in 3.2.1

References 9