An issue was discovered in Python before 3.11.1. An...
High severity
Unreviewed
Published
Nov 9, 2022
to the GitHub Advisory Database
•
Updated Sep 16, 2023
Description
Published by the National Vulnerability Database
Nov 9, 2022
Published to the GitHub Advisory Database
Nov 9, 2022
Last updated
Sep 16, 2023
An issue was discovered in Python before 3.11.1. An unnecessary quadratic algorithm exists in one path when processing some inputs to the IDNA (RFC 3490) decoder, such that a crafted, unreasonably long name being presented to the decoder could lead to a CPU denial of service. Hostnames are often supplied by remote servers that could be controlled by a malicious actor; in such a scenario, they could trigger excessive CPU consumption on the client attempting to make use of an attacker-supplied supposed hostname. For example, the attack payload could be placed in the Location header of an HTTP response with status code 302. A fix is planned in 3.11.1, 3.10.9, 3.9.16, 3.8.16, and 3.7.16.
References