CVE-2022-42919

python: local privilege escalation via the multiprocessing forkserver start method

Published Nov 6, 2022 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3980-1 python3.9 security update
EUVD EUVD EUVD-2022-45976 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.
Ubuntu USN Ubuntu USN USN-5713-1 Python vulnerability
Ubuntu USN Ubuntu USN USN-5888-1 Python vulnerabilities
Ubuntu USN Ubuntu USN USN-6891-1 Python vulnerabilities
References
Link Providers
https://github.com/python/cpython/compare/v3.10.8...v3.10.9 cve-icon cve-icon
https://github.com/python/cpython/compare/v3.9.15...v3.9.16 cve-icon cve-icon
https://github.com/python/cpython/issues/97514 cve-icon cve-icon cve-icon
https://github.com/python/cpython/issues/97514#issuecomment-1310277840 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2024/12/msg00000.html cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FKGCQPIVHEAIJ77R3RSNSQWYBUDVWDKU/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/P2LHWWEI5OBQ6RELULMVU6KMDYG4WZXH/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PI5DYIED6U26BGX5IRZWNCP6TY4M2ZGZ/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QLUGZSEAO3MBWGKCUSMKQIRYJZKJCIOB/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R6KGIRHSENZ4QAB234Z36HVIDTRJ3MFI/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RDK3ZZBRYFO47ET3N4BNTKVXN47U6ICY/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VCRKBB5Y5EWTJUNC7LK665WO64DDXSTN/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XX6LLAXGZVZ327REY6MDZRMMP47LJ53P/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2022-42919 cve-icon
https://security.gentoo.org/glsa/202305-02 cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20221209-0006/ cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2022-42919 cve-icon
History
Type Values Removed Values Added
Weaknesses CWE-502
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Nov 3, 2025, 9:46 PM
Reserved
Oct 14, 2022, 12:00 AM
Status
Modified
Published
Nov 7, 2022, 12:15 AM
Modified
Jun 17, 2026, 5:05 AM
Severity
Important
Public date
Oct 26, 2022, 12:00 AM