HOMEVULNERABILITIESCVE-2021-3406
CRITICAL

CVE-2021-3406

CWE-347Published: February 25, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

A flaw was found in keylime 5.8.1 and older. The issue in the Keylime agent and registrar code invalidates the cryptographic chain of trust from the Endorsement Key certificate to agent attestations.

NVD Source

Technical Analysis

CVE-2021-3406 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), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

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

Affected Vendors & Products

Fedora1 product(s)
fedora
keylime1 product(s)
keylime
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

ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=1932469
ADVISORYhttps://github.com/keylime/keylime/security/advisories/GHSA-78f8-6c68-375m
ADVISORYhttps://bugzilla.redhat.com/show_bug.cgi?id=1932469
ADVISORYhttps://github.com/keylime/keylime/security/advisories/GHSA-78f8-6c68-375m

All References (6)

→
https://bugzilla.redhat.com/show_bug.cgi?id=1932469Issue Tracking · Third Party Advisory
→
https://github.com/keylime/keylime/security/advisories/GHSA-78f8-6c68-375mThird Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YAWKEF2LVXUME266T6RNRVBGAD375QAT/
→
https://bugzilla.redhat.com/show_bug.cgi?id=1932469Issue Tracking · Third Party Advisory
→
https://github.com/keylime/keylime/security/advisories/GHSA-78f8-6c68-375mThird Party Advisory
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YAWKEF2LVXUME266T6RNRVBGAD375QAT/

Quick Facts

CVE IDCVE-2021-3406
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-347
CISA KEVNo
Affected2 vendor(s)
PublishedFeb 25, 2021

Related CVEs (CWE-347)

CVE-2026-48558
KEV10.0
CVE-2026-56451
10.0
CVE-2024-32962
10.0
CVE-2026-44748
9.9
CVE-2025-8454
9.8
CVE-2024-41138
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-3406 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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