HOMEVULNERABILITIESCVE-2021-22212
HIGH

CVE-2021-22212

CWE-327Published: June 8, 2021· Updated: Jun 17, 2026

7.4
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2021-22212 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 7.4.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected Vendors & Products

Fedora1 product(s)
fedora
ntpsec1 product(s)
ntpsec
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=1955859
PATCHhttps://gitlab.com/NTPsec/ntpsec/-/issues/699
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=1955859
PATCHhttps://gitlab.com/NTPsec/ntpsec/-/issues/699
ADVISORYhttps://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.json
ADVISORYhttps://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.json

All References (8)

→
https://bugzilla.redhat.com/show_bug.cgi?id=1955859Issue Tracking · Patch · Third Party Advisory
→
https://gitlab.com/NTPsec/ntpsec/-/issues/699Issue Tracking · Patch · Third Party Advisory
→
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsonThird Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/
→
https://bugzilla.redhat.com/show_bug.cgi?id=1955859Issue Tracking · Patch · Third Party Advisory
→
https://gitlab.com/NTPsec/ntpsec/-/issues/699Issue Tracking · Patch · Third Party Advisory
→
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22212.jsonThird Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3GIT2HYL5BQXPGKI6ZDNG473IEQ5WQF2/

Quick Facts

CVE IDCVE-2021-22212
CVSS Score7.4 / 10
SeverityHIGH
WeaknessCWE-327
CISA KEVNo
Affected2 vendor(s)
PublishedJun 8, 2021

Related CVEs (CWE-327)

CVE-2026-50086
10.0
CVE-2025-54426
9.9
CVE-2020-10377
9.8
CVE-2017-9859
9.8
CVE-2019-16143
9.8
CVE-2014-9969
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-22212 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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