CVE-2022-42917

Severity: medium (CVSS 6.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-14 · updated 2026-09-22
Weakness: CWE-367

Description

In FRRouting FRR before 8.5, the service user (usually frr) can escalate its privileges to root by monitoring the configuration directory (/etc/frr) and replacing config files upon creation with, for example, symlinks to change the ownership of arbitrary files. This is a TOCTOU Race Condition caused by a combination of touch and chown.

Affected products

FRRouting: before 4.5 — fixed in 4.5

How to fix

Upgrade to a fixed version: FRRouting 4.5. Check the vendor advisory for mitigations.

References

https://bugzilla.suse.com/show_bug.cgi?id=1204124
https://frrouting.org/security/cve-2022-42917/
https://github.com/FRRouting/frr/commit/972cdc560e339d70c0ee5fb70ec636ab78f00bca
https://github.com/FRRouting/frr/compare/frr-8.4...frr-8.5

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