Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2021-20322
n/a kernel — A flaw in the processing of received ICMP errors (ICMP fragment needed and ICMP redirect) in the Linux kernel functionality was found to …
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H N N U H H N 7.4 .0690 93.9 —
AFFECTED
Product Versions Fixed
kernel 4.15 – —
TIMELINE
Dec 17 Reserved by redhat
Feb 18 Published (CNA: redhat)
Jul 30 ENRICHED — CVE-2021-20322 (kernel). Received CVSS 7.4 and CPE data from NVD.
Description
A flaw in the processing of received ICMP errors (ICMP fragment needed and ICMP redirect) in the Linux kernel functionality was found to allow the ability to quickly scan open UDP ports. This flaw allows an off-path remote user to effectively bypass the source port UDP randomization. The highest threat from this vulnerability is to confidentiality and possibly integrity, because software that relies on UDP source port randomization are indirectly affected as well.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| December 17, 2020 | Reserved | Reserved by redhat |
| February 18, 2022 | Published | Published (CNA: redhat) |
| July 30, 2026 | ENRICHED | ENRICHED — CVE-2021-20322 (kernel). Received CVSS 7.4 and CPE data from NVD. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| n/a | kernel | — | 4.15 | — |
References (9)
- https://bugzilla.redhat.com/show_bug.cgi?id=2014230 [Issue Tracking, Third Party Advisory]
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810 [Mailing List, Patch, Vendor Advisory]
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1 [Mailing List, Patch, Vendor Advisory]
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv4/route.c?h=v5.15-rc6&id=67d6d681e15b578c1725bad8ad079e05d1c48a8e [Mailing List, Patch, Vendor Advisory]
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv6/route.c?h=v5.15-rc6&id=a00df2caffed3883c341d5685f830434312e4a43 [Mailing List, Patch, Vendor Advisory]
- https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html [Mailing List, Third Party Advisory]
- https://security.netapp.com/advisory/ntap-20220303-0002/ [Third Party Advisory]
- https://www.debian.org/security/2022/dsa-5096 [Third Party Advisory]
- https://www.oracle.com/security-alerts/cpujul2022.html [Third Party Advisory]
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-20322 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
