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No exploitation reportedFix available

CVE-2021-22212

No exploitation reported by the sources we read.

  • Published2021-06-08
  • WeaknessCWE-327

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2021-06-0813:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 15:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-22212?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-22212?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Ntpsec
BranchAffectedFixed in
1.2= 1.2.0no fix published
Fedoraproject fedora
BranchAffectedFixed in
34.x= 34no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • ntpsecopenSUSE:Tumbleweedall versions · fixed in 1.2.1-1.2
  • ntpsecDebian:14all versions · fixed in 1.2.0+dfsg1-4
  • ntpsecDebian:13all versions · fixed in 1.2.0+dfsg1-4
  • ntpsecDebian:12all versions · fixed in 1.2.0+dfsg1-4
  • ntpsecCleanStartall versions · fixed in 1.2.1-r0
  • ntpsecAlpine:v3.24all versions · fixed in 1.2.1-r0
  • ntpsecAlpine:v3.23all versions · fixed in 1.2.1-r0
  • ntpsecAlpine:v3.22all versions · fixed in 1.2.1-r0

8 more package ranges on OSV.dev

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • CNACVSS 3.14known since 2026-10-23
  • NVDCVSS 3.17.4read 2026-10-23
  • NVDCVSS 2.05.8read 2026-10-23
  • NVDweakness (CWE)CWE-327read 2026-10-23
  • FIRST EPSSEPSS score0.5 %2026-11-03
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
2021-06-08
Last Modified
2026-06-17
NVD status
Modified

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.

Is CVE-2021-22212 actively exploited?

Active exploitation of CVE-2021-22212 has not been confirmed. Its EPSS score was 0.5% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-22212?

CVE-2021-22212 has a CVSS v3 base score of 7.4 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.

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Sources for this record