CVE-2021-3772Network attack vector

Association termination via invalid SCTP chunks

Published Mar 2, 2022 · Updated Aug 3, 2024

Improper validation of integrity check value in Linux Kernel before 5.15 allows remote attackers to terminate SCTP associations via spoofed packets. The net/sctp state-machine handlers accepted chunks without verifying the association verification tag and generated ABORT responses with an incorrect tag, allowing invalid packets to reach association-processing logic. The attacker needs the association IP addresses and ports and the ability to send spoofed source addresses; impact is service interruption of the targeted SCTP association.

CVSS severity6.5
Medium
EPSS probability1.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper validation of integrity check value in Linux Kernel before 5.15 allows remote attackers to terminate SCTP associations via spoofed packets. The net/sctp state-machine handlers accepted chunks without verifying the association verification tag and generated ABORT responses with an incorrect tag, allowing invalid packets to reach association-processing logic. The attacker needs the association IP addresses and ports and the ability to send spoofed source addresses; impact is service interruption of the targeted SCTP association.

The record

CVE
CVE-2021-3772
Published
Mar 2, 2022
Updated
Aug 3, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-354, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 2, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in linux kernel v5.15 and above

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Fixed in linux kernel v5.15 and above

Published CVSS scores

5.8NVDAV:N/AC:M/Au:N/C:N/I:P/A:P
6.5NVDCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-354Improper Validation of Integrity Check Value
T1498Network Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo