CVE-2021-22212

low-risk
Published 2021-06-08

ntpkeygen can generate keys that ntpd fails to parse. NTPsec 1.2.0 allows ntpkeygen to generate keys with '#' characters. ntpd then either pads, shortens the key, or fails to load these keys entirely, depending on the key type and the placement of the '#'. This results in the administrator not being able to use the keys as expected or the keys are shorter than expected and easier to brute-force, possibly resulting in MITM attacks between ntp clients and ntp servers. For short AES128 keys, ntpd generates a warning that it is padding them.

Do I need to act?

-
0.13% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.0/10 Medium
LOCAL / HIGH complexity

Affected Products (2)

Affected Vendors

18
/ 100
low-risk
Severity 10/34 · Low
Exploitability 1/34 · Minimal
Exposure 7/34 · Low