CVE-2022-42917: Race Condition
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 Software
Event History
Frequently Asked Questions
Which deployments are affected?
FRRouting installations running a version before 8.5 are affected. The issue involves the FRR configuration directory, /etc/frr.
What access does an attacker need?
An attacker needs the ability to act as the FRR service user, usually frr, and monitor /etc/frr for configuration files as they are created.
What is the practical impact of successful exploitation?
The service user can escalate privileges to root by replacing newly created configuration files, such as with symlinks. This can cause ownership changes to arbitrary files.