What it is
Time synchronization (123/udp).
Why it is risky
Open NTP can be abused (e.g. monlist) for amplification DDoS.
What to do
Stay patched, disable monlist, and restrict externally if not needed.
Is it listening on your server?
Linux
ss -ltnp 'sport = :123'Track these versions on your own servers
InfraGuard collects installed software versions from every server and flags the ones with known vulnerabilities. Self-hosted — nothing leaves your network.