Bleeping Computer
The Python standard library ipaddress also suffers from the critical IP address validation vulnerability identical to the flaw that was reported in the “netmask” library earlier this year.
The researchers who had discovered the critical flaw in netmask, also discovered the same flaw in this Python module and have procured a vulnerability identifier: CVE-2021-29921.
The regression bug crept into Python 3.x’s ipaddress module as a result of a change made in 2019 by Python maintainers.