A flaw was found in KubeVirt's virt-handler network cache handling. The WriteToCachedFile function writes data to a launcher-rooted path using os.WriteFile and os.Chown without symlink protection. A user with access to the virt-launcher container can plant a symlink at the cache file path, causing virt-handler to follow it and overwrite an arbitrary host file with JSON content and change its ownership.
Exploitability
AV:LAC:HPR:LUI:NScope
S:CImpact
C:NI:LA:L4.2/CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:LOther