CVE-2014-9293

What it actually does

The config_auth function generates a predictable authentication key when none is explicitly configured, allowing remote attackers to brute-force the key and bypass NTP cryptographic protections.

Why it matters to the business

Attackers can manipulate time synchronization on unpatched systems, potentially disrupting logging accuracy, certificate validation, and scheduled operations across networks that still run vulnerable NTP versions.

How an attack unfolds

An attacker sends crafted NTP packets to a daemon lacking an explicit auth key; because the generated key is weak, the attacker performs an offline brute-force to recover it and then forges authenticated responses to alter time data.

How to fix it

Upgrade ntpd to version 4.2.7p11 or later and configure a strong authentication key; if upgrade is impossible, restrict NTP access to trusted peers only.

How to confirm the fix worked

Run 'ntpq -c rv' or inspect ntpd configuration to verify the running version is at least 4.2.7p11 and that an auth key is explicitly defined; retest with a key-brute-force tool in a lab environment.

Typical attack path

1. Identify publicly reachable NTP servers running versions before 4.2.7p11
2. Confirm absence of a manually configured auth key
3. Capture NTP traffic to obtain the weak key material
4. Brute-force the generated key offline
5. Forge authenticated NTP responses to shift system time

How to detect it

Search historical packet captures and logs for NTP packets lacking expected authentication or showing repeated unauthenticated queries from external addresses; review system time change events around periods of high NTP traffic.

What your security team should do

• Immediately inventory all NTP deployments and replace any version older than 4.2.7p11
• Enforce explicit strong auth keys on all remaining NTP instances
• Monitor EPSS and exploit availability trends for any resurgence in scanning activity