Is CVE-2021-20322 in the CISA KEV catalog?

No. CVE-2021-20322 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-20322?

CVE-2021-20322 has a CVSS v3 base score of 7.4 (HIGH).

What is the EPSS score for CVE-2021-20322?

CVE-2021-20322 has an EPSS score of 6.90% (93th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-20322?

Upgrade linux on debian 11 to 5.10.70-1 or later. Fixes are available for 44 affected products.

CVE & CISA-KEV Catalog

CVE-2021-20322

HIGHEPSS 93th pctl

7.4

CVSS v3

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.

CWE-330

How to fix

Remediation Available

linuxDebian

Fixed in:5.10.70-1CVE-2021-20322

Fixed in:5.14.6-1CVE-2021-20322

linuxUbuntu

Fixed in:4.15.0-167.175USN-5268-1

linux-awsUbuntu

Fixed in:4.15.0-1119.127USN-5268-1

linux-aws-hweUbuntu

Fixed in:4.15.0-1119.126~16.04.2USN-5268-1

linux-azureUbuntu

Fixed in:4.15.0-1130.143~14.04.1USN-5268-1

Fixed in:4.15.0-1130.143~16.04.1USN-5268-1

linux-dell300xUbuntu

Fixed in:4.15.0-1034.39USN-5268-1

linux-gcpUbuntu

Fixed in:4.15.0-1115.129~16.04.1USN-5268-1

linux-gcp-4.15Ubuntu

Fixed in:4.15.0-1115.129USN-5268-1

linux-hweUbuntu

Fixed in:4.15.0-167.175~16.04.1USN-5268-1

linux-image-4.15.0-1034-dell300xUbuntu

Fixed in:4.15.0-1034.39USN-5268-1

linux-image-4.15.0-1086-oracleUbuntu

Fixed in:4.15.0-1086.94~16.04.1USN-5268-1

Fixed in:4.15.0-1086.94USN-5268-1

linux-image-4.15.0-1102-raspi2Ubuntu

Fixed in:4.15.0-1102.109USN-5268-1

linux-image-4.15.0-1106-kvmUbuntu

Fixed in:4.15.0-1106.108USN-5268-1

linux-image-4.15.0-1115-gcpUbuntu

Fixed in:4.15.0-1115.129~16.04.1USN-5268-1

Fixed in:4.15.0-1115.129USN-5268-1

linux-image-4.15.0-1119-snapdragonUbuntu

Fixed in:4.15.0-1119.128USN-5268-1

linux-image-4.15.0-1130-azureUbuntu

Fixed in:4.15.0-1130.143~14.04.1USN-5268-1

Fixed in:4.15.0-1130.143~16.04.1USN-5268-1

linux-image-4.15.0-167-genericUbuntu

Fixed in:4.15.0-167.175~16.04.1USN-5268-1

Fixed in:4.15.0-167.175USN-5268-1

linux-image-4.15.0-167-generic-lpaeUbuntu

Fixed in:4.15.0-167.175USN-5268-1

linux-image-4.15.0-167-lowlatencyUbuntu

Fixed in:4.15.0-167.175~16.04.1USN-5268-1

Fixed in:4.15.0-167.175USN-5268-1

linux-image-aws-hweUbuntu

Fixed in:4.15.0.1119.110USN-5268-1

linux-image-aws-lts-18.04Ubuntu

Fixed in:4.15.0.1119.122USN-5268-1

linux-image-azureUbuntu

Fixed in:4.15.0.1130.103USN-5268-1

Fixed in:4.15.0.1130.121USN-5268-1

linux-image-dell300xUbuntu

Fixed in:4.15.0.1034.36USN-5268-1

linux-image-gcpUbuntu

Fixed in:4.15.0.1115.116USN-5268-1

linux-image-gcp-lts-18.04Ubuntu

Fixed in:4.15.0.1115.134USN-5268-1

linux-image-genericUbuntu

Fixed in:4.15.0.167.156USN-5268-1

linux-image-generic-hwe-16.04Ubuntu

Fixed in:4.15.0.167.159USN-5268-1

linux-image-generic-lpaeUbuntu

Fixed in:4.15.0.167.156USN-5268-1

linux-image-gkeUbuntu

Fixed in:4.15.0.1115.116USN-5268-1

linux-image-kvmUbuntu

Fixed in:4.15.0.1106.102USN-5268-1

linux-image-lowlatencyUbuntu

Fixed in:4.15.0.167.156USN-5268-1

linux-image-lowlatency-hwe-16.04Ubuntu

Fixed in:4.15.0.167.159USN-5268-1

linux-image-lowlatency-hwe-16.04-edgeUbuntu

Fixed in:4.15.0.167.159USN-5268-1

linux-image-oemUbuntu

Fixed in:4.15.0.167.159USN-5268-1

linux-image-oracleUbuntu

Fixed in:4.15.0.1086.74USN-5268-1

linux-image-oracle-lts-18.04Ubuntu

Fixed in:4.15.0.1086.96USN-5268-1

linux-image-raspi2Ubuntu

Fixed in:4.15.0.1102.100USN-5268-1

linux-image-snapdragonUbuntu

Fixed in:4.15.0.1119.122USN-5268-1

linux-image-virtualUbuntu

Fixed in:4.15.0.167.156USN-5268-1

linux-image-virtual-hwe-16.04Ubuntu

Fixed in:4.15.0.167.159USN-5268-1

linux-kvmUbuntu

Fixed in:4.15.0-1106.108USN-5268-1

linux-oracleUbuntu

Fixed in:4.15.0-1086.94~16.04.1USN-5268-1

Fixed in:4.15.0-1086.94USN-5268-1

linux-raspi2Ubuntu

Fixed in:4.15.0-1102.109USN-5268-1

linux-snapdragonUbuntu

Fixed in:4.15.0-1119.128USN-5268-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

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

Exploit Intelligence

6.90%probability of exploitation in 30 days

93rdpercentile

High risk: more likely to be exploited than 93% of all known CVEs.

References

Patch4

Third-Party Advisory5

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.