[USN-5138-1] python-py vulnerability

========================================================================== Ubuntu Security Notice USN-5138-1 November 10, 2021
python-py vulnerability ==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.04 LTS – Ubuntu 18.04 LTS
python-py could be made to crash if provided with specially crafted input.
Software Description: – python-py: Advanced Python development support library
The py.path.svnwc component of py (aka python-py) through v1.9.0 contains a regular expression with an ambiguous subpattern that is susceptible to catastrophic backtracing. This could be used by attackers to cause a compute-time denial of service attack by supplying malicious input to the blame functionality.
Update instructions:
The problem can be corrected by updating your system to the following package versions:
Ubuntu 20.04 LTS: pypy-py 1.8.1-1ubuntu0.1 python-py 1.8.1-1ubuntu0.1 python3-py 1.8.1-1ubuntu0.1
Ubuntu 18.04 LTS: pypy-py 1.5.2-1ubuntu0.1 python-py 1.5.2-1ubuntu0.1 python3-py 1.5.2-1ubuntu0.1
In general, a standard system update will make all the necessary changes.
References: ubuntu.com/security/notices/USN-5138-1 CVE-2020-29651
Package Information: launchpad.net/ubuntu/+source/python-py/1.8.1-1ubuntu0.1 launchpad.net/ubuntu/+source/python-py/1.5.2-1ubuntu0.1