How severe is CVE-2021-22212?

CVE-2021-22212 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-22212 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-22212?

CVE-2021-22212 primarily affects Ntpsec. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-22212?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-22212 published?

CVE-2021-22212 was published on 2021-06-08 and last updated on 2026-06-17.

CVE-2021-22212

CVE-2021-22212 is a medium-severity vulnerability in Ntpsec with a CVSS 3.x base score of 4.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-327.

Key facts

Severity: Medium (CVSS 3.x base score 4.0)
CVSS v2: 5.8
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-327
Affected product: Ntpsec
Published: 2021-06-08
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-22212?: 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.
How severe is CVE-2021-22212?: CVE-2021-22212 has a CVSS 3.x base score of 4.0, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-22212 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-22212?: CVE-2021-22212 primarily affects Ntpsec. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-22212?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-22212 published?: CVE-2021-22212 was published on 2021-06-08 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:ntpsec:ntpsec:1.2.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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