CVE-2022-42919

Python 3.9.x before 3.9.16 and 3.10.x before 3.10.9 on Linux allows local
privilege escalation in a non-default configuration. The Python
multiprocessing library, when used with the forkserver start method on
Linux, allows pickles to be deserialized from any user in the same machine
local network namespace, which in many system configurations means any user
on the same machine. Pickles can execute arbitrary code. Thus, this allows
for local user privilege escalation to the user that any forkserver process
is running as. Setting multiprocessing.util.abstract_sockets_supported to
False is a workaround. The forkserver start method for multiprocessing is
not the default start method. This issue is Linux specific because only
Linux supports abstract namespace sockets. CPython before 3.9 does not make
use of Linux abstract namespace sockets by default. Support for users
manually specifying an abstract namespace socket was added as a bugfix in
3.7.8 and 3.8.3, but users would need to make specific uncommon API calls
in order to do that in CPython before 3.9.

Bugs

• <https://github.com/python/cpython/issues/97514&gt;