CVE-2020-13776

Published: 03 June 2020

systemd through v245 mishandles numerical usernames such as ones composed of decimal digits or 0x followed by hex digits, as demonstrated by use of root privileges when privileges of the 0x0 user account were intended. NOTE: this issue exists because of an incomplete fix for CVE-2017-1000082.

Priority

Low

CVSS 3 base score: 6.7

Status

Package Release Status
systemd
Launchpad, Ubuntu, Debian
Upstream
Released (246-2)
Ubuntu 20.10 (Groovy Gorilla) Not vulnerable
(246.6-1ubuntu1)
Ubuntu 20.04 LTS (Focal Fossa) Ignored

Ubuntu 18.04 LTS (Bionic Beaver) Ignored

Ubuntu 16.04 LTS (Xenial Xerus) Ignored

Ubuntu 14.04 ESM (Trusty Tahr) Ignored

Patches:
Upstream: https://github.com/systemd/systemd/commit/156a5fd297b61bce31630d7a52c15614bf784843
Upstream: https://github.com/systemd/systemd/commit/6495ceddf38aed2c9efdcf9d3440140190800b55

Notes

AuthorNote
mdeslaur
The administrator would have to create a systemd service unit
with a numerical username or a username starting with 0x as a
User= value, and that particular userid would need to exist on
the system. Setting priority to low due to this unlikely
scenario.

Fixing this requires an extensive backport that refactors
integer parsing in systemd and the risk of regressions stemming
from the behavioural change outweighs the severity of this
issue. We will not be fixing this issue in stable Ubuntu
releases.

References

Bugs