USN-5200-1: Python vulnerabilities
17 December 2021
Python could be made to crash if it receives specially crafted input from a malicious server.
Releases
Packages
- python3.7 - An interactive high-level object-oriented language
- python3.8 - An interactive high-level object-oriented language
Details
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex allowing for catastrophic backtracking. Specially
crafted traffic from a malicious HTTP server could cause a regular expression
denial of service (ReDoS) condition for a client.
(CVE-2020-8492)
It was discovered that the urllib.request.AbstractBasicAuthHandler class
in Python contains regex with a quadratic worst-case time complexity.
Specially crafted traffic from a malicious HTTP server could cause a regular
expression denial of service (ReDoS) condition for a client.
(CVE-2021-3733)
It was discovered that the Python urllib http client could enter into an infinite
loop when incorrectly handling certain server responses (100 Continue response).
Specially crafted traffic from a malicious HTTP server could cause a denial of
service (DoS) condition for a client.
(CVE-2021-3737)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 18.04
-
python3.7-minimal
-
3.7.5-2ubuntu1~18.04.2
-
libpython3.8-stdlib
-
3.8.0-3ubuntu1~18.04.2
-
libpython3.7-stdlib
-
3.7.5-2ubuntu1~18.04.2
-
python3.7
-
3.7.5-2ubuntu1~18.04.2
-
python3.8
-
3.8.0-3ubuntu1~18.04.2
-
python3.8-minimal
-
3.8.0-3ubuntu1~18.04.2
In general, a standard system update will make all the necessary changes.