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Public proof of conceptFix available

CVE-2021-43267

A public proof of concept exists; no exploitation attested.

  • Published2021-11-02
  • WeaknessCWE-1284

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

An issue was discovered in net/tipc/crypto.c in the Linux kernel before 5.14.16. The Transparent Inter-Process Communication (TIPC) functionality allows remote attackers to exploit insufficient validation of user-supplied sizes for the MSG_CRYPTO message type.

Timeline

dates in UTC
  1. 2021-11-0223:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-03 21:37 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-2021-43267?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-43267?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Fedoraproject fedora
BranchAffectedFixed in
34.x= 34no fix published
35.x= 35no fix published
Linux linux kernel
BranchAffectedFixed in
5.x≥ 5.11, < 5.14.165.14.16
5.10≥ 5.10, < 5.10.775.10.77
Netapp h300e firmwareversion to verify
BranchAffectedFixed in
—all versionsno fix published

6 more products in the sources.

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

  • :linux_kernel:Androidfrom :0 · fixed in :2022-03-05
  • kernelRocky Linux:8all versions · fixed in 0:4.18.0-348.2.1.el8_5
  • kernelRed Hat:rhel_eus:8.4::baseosall versions · fixed in 0:4.18.0-305.28.1.el8_4and 32 other packages
  • kernelRed Hat:enterprise_linux:8::baseosall versions · fixed in 0:4.18.0-348.2.1.el8_5and 32 other packages
  • kernelMageia:8all versions · fixed in 5.10.78-1.mga8and 1 other package
  • kernelAzure Linux:2all versions · fixed in 5.10.78.1-1
  • kernel-debuginfoRed Hat:rhel_eus:8.4::crball versions · fixed in 0:4.18.0-305.28.1.el8_4and 9 other packages
  • kernel-debuginfoRed Hat:enterprise_linux:8::crball versions · fixed in 0:4.18.0-348.2.1.el8_5and 9 other packages

32 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-43267 Red Hat Product Security365 products fixed

    kernel: Insufficient validation of user-supplied sizes for the MSG_CRYPTO message type

  • RHSA-2021:4750 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: Red Hat Virtualization Host security and bug fix update [ovirt-4.4.9] 0-day

  • RHSA-2021:4647 Red Hat Product Security120 products fixed

    Red Hat Security Advisory: kernel security update

  • RHSA-2021:4650 Red Hat Product Security120 products fixed

    Red Hat Security Advisory: kernel security, bug fix, and enhancement update

  • RHSA-2021:4644 Red Hat Product Security56 products fixed

    Red Hat Security Advisory: kpatch-patch security update

  • RHSA-2021:4645 Red Hat Product Security7 products fixed

    Red Hat Security Advisory: kpatch-patch security update

2 more advisories

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2021:4750 · 2 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/2974891
  2. Vendor fix Red Hat Product Security RHSA-2021:4647 · 120 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect.
  3. Vendor fix Red Hat Product Security RHSA-2021:4644 · 56 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  4. Workaround from the vendor Red Hat Product Security RHSA-2021:4750 · 6 productsThe TIPC module will NOT be automatically loaded. When required, administrative action is needed to explicitly load this module. Loading the module can be prevented with the following instructions: # echo "install tipc /bin/true" >> /etc/modprobe.d/disable-tipc.conf The system will need to be res…

Advisories and patches

Detection

read 2026-11-03 22:42 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
2 repositories, unverifiedDarkSprings/CVE-2021-43267-POCzzhacked/CVE-2021-43267
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-1284read 2026-10-23
  • FIRST EPSSEPSS score57.9 %read 2026-11-03
  • PoC-in-GitHubproof of concept2read 2026-11-03
  • OSVaffected packages—

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2021-11-02
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2021-43267?

An issue was discovered in net/tipc/crypto.c in the Linux kernel before 5.14.16. The Transparent Inter-Process Communication (TIPC) functionality allows remote attackers to exploit insufficient validation of user-supplied sizes for the MSG_CRYPTO message type.

Is CVE-2021-43267 actively exploited?

Active exploitation of CVE-2021-43267 has not been confirmed. Its EPSS score was 57.9% on 2026-11-03, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-43267?

CVE-2021-43267 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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