CVE-2021-20322: debian debian_linux Use of Insufficiently Random Values

Analyzed

AliasesSUSE-SU-2021:4057-1SUSE-SU-2021:4075-1UBUNTU-CVE-2021-20322+1 more

Published 18-02-2022Last modified 30-07-2026

Vulnerability summary

CVE-2021-20322 is a high (CVSS 7.4) Use of Insufficiently Random Values vulnerability in debian debian_linux. EPSS estimates a 6.90% chance of exploitation in the next 30 days, higher than 94% of scored vulnerabilities.

Priority

Prioritisesevere

Severe, CVSS 7.4 (NVD); no exploitation reported by the 5 checked sources; EPSS 7% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?

CVSS score

7.4/10

010

High · v3.1 (NVD)

EPSS score

6.90%

0%100%

Low · 0.00 pp in 30 days

KEVNot listedNot listed by any tracked catalog.

RansomwareNot flaggedNo ransomware use recorded.

Public exploits0No public exploits recorded

Timeline

18-02-2022
PublishedVulnerability first disclosed.
30-07-2026
Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 3 sources · 3 versions

v4.09.1v3.17.4v2.05.8

EPSS trend

Probability

6.90%

Chance of exploitation in the next 30 days

Percentile

94%

Versus all other CVEs

30-day change

No change 0.00 pp

From 6.90% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs

CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

CWE-330Use of Insufficiently Random ValuesThe product uses insufficiently random numbers or values in a security context that depends on unpredictable numbers.

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu62 products

linuxAll versions (No fix recorded) | < 4.15.0-167.175 | < 5.4.0-92.103
linux-awsAll versions (No fix recorded) | < 4.15.0-1119.127 | < 5.4.0-1061.64
linux-aws-5.0All versions (No fix recorded)
linux-aws-5.11< 5.11.0-1021.22~20.04.2
linux-aws-5.3All versions (No fix recorded)

linux-aws-5.4< 5.4.0-1061.64~18.04.1
linux-aws-5.8All versions (No fix recorded)
linux-aws-fips< 4.15.0-2060.62 | All versions (No fix recorded) | < 5.4.0-1069.73+fips2
linux-aws-hwe< 4.15.0-1119.126~16.04.2
linux-azure< 4.15.0-1130.143~14.04.1 | < 4.15.0-1130.143~16.04.1 | All versions (No fix recorded) | < 5.4.0-1065.68
linux-azure-4.15< 4.15.0-1131.144
linux-azure-5.11< 5.11.0-1021.22~20.04.1
linux-azure-5.3All versions (No fix recorded)
linux-azure-5.4< 5.4.0-1065.68~18.04.1
linux-azure-5.8All versions (No fix recorded)
linux-azure-edgeAll versions (No fix recorded)
linux-azure-fde-5.15< 5.15.0-1114.123~20.04.1
linux-azure-fips< 4.15.0-2042.46 | All versions (No fix recorded) | < 5.4.0-1073.76+fips1
linux-bluefield< 5.4.0-1023.26
linux-dell300x< 4.15.0-1034.39
linux-fipsAll versions (No fix recorded) | < 4.15.0-1076.85 | < 5.4.0-1038.44
linux-gcp< 4.15.0-1115.129~16.04.1 | All versions (No fix recorded) | < 5.4.0-1059.63
linux-gcp-4.15< 4.15.0-1115.129
linux-gcp-5.11< 5.11.0-1022.24~20.04.1
linux-gcp-5.3All versions (No fix recorded)
linux-gcp-5.4< 5.4.0-1059.63~18.04.1
linux-gcp-5.8All versions (No fix recorded)
linux-gcp-fips< 4.15.0-2025.27 | All versions (No fix recorded) | < 5.4.0-1067.71~20.04.1
linux-gke< 5.4.0-1057.60
linux-gke-4.15All versions (No fix recorded)
linux-gke-5.4< 5.4.0-1057.60~18.04.1
linux-gkeop< 5.4.0-1029.30
linux-gkeop-5.4< 5.4.0-1029.30~18.04.2
linux-hwe< 4.15.0-167.175~16.04.1 | All versions (No fix recorded)
linux-hwe-5.11All versions (No fix recorded)
linux-hwe-5.4< 5.4.0-92.103~18.04.2
linux-hwe-5.8All versions (No fix recorded)
linux-hwe-edgeAll versions (No fix recorded)
linux-ibm< 5.4.0-1010.11
linux-intel-5.13All versions (No fix recorded)
linux-intel-iot-realtimeAll versions (No fix recorded)
linux-kvmAll versions (No fix recorded) | < 4.15.0-1106.108 | < 5.4.0-1051.53
linux-lts-xenialAll versions (No fix recorded)
linux-oemAll versions (No fix recorded)
linux-oem-5.10< 5.10.0-1050.52
linux-oem-5.13< 5.13.0-1019.23
linux-oem-5.6All versions (No fix recorded)
linux-oracle< 4.15.0-1086.94~16.04.1 | < 4.15.0-1086.94 | < 5.4.0-1059.63
linux-oracle-5.0All versions (No fix recorded)
linux-oracle-5.11< 5.11.0-1021.22~20.04.1
linux-oracle-5.3All versions (No fix recorded)
linux-oracle-5.4< 5.4.0-1059.63~18.04.1
linux-oracle-5.8All versions (No fix recorded)
linux-raspi< 5.4.0-1048.53
linux-raspi-5.4< 5.4.0-1048.53~18.04.1
linux-raspi-realtimeAll versions (No fix recorded)
linux-raspi2< 4.15.0-1102.109 | All versions (No fix recorded)
linux-realtimeAll versions (No fix recorded)
linux-riscvAll versions (No fix recorded)
linux-riscv-5.11< 5.11.0-1022.23~20.04.1
linux-riscv-5.8All versions (No fix recorded)
linux-snapdragon< 4.15.0-1119.128

Show all 62

Suse25 products

kernel-livepatch-SLE15-SP2_Update_12&distro=SUSE Linux Enterprise Live Patching 15 SP2< 9-2.1
kernel-livepatch-SLE15-SP2_Update_13&distro=SUSE Linux Enterprise Live Patching 15 SP2< 9-2.1
kernel-livepatch-SLE15-SP2_Update_14&distro=SUSE Linux Enterprise Live Patching 15 SP2< 7-2.1
kernel-livepatch-SLE15-SP2_Update_16&distro=SUSE Linux Enterprise Live Patching 15 SP2< 7-2.1
kernel-livepatch-SLE15-SP2_Update_17&distro=SUSE Linux Enterprise Live Patching 15 SP2< 6-2.1

Show all 25

Netapp15 products

active_iq_unified_managerna
aff_a700s_firmwarena
aff_baseboard_management_controllerna
e-series_santricity_os_controller≥ 11.0, ≤ 11.70.1
fas_baseboard_management_controllerna

Show all 15

Oracle3 products

Debian2 products

linux< 5.14.6-1
debian_linuxEOL9.0 | 10.0

Fedoraproject1 product

fedoraEOL34

Linux1 product

linux_kernel≥ 4.15, < 4.19.215 | ≥ 4.20, < 5.4.157 | ≥ 5.5, < 5.10.62 | ≥ 5.11, < 5.13.14

7 vendors · 109 products

References

18 links

bugzilla.redhat.com/show_bug.cgi?id=2014230X Refsource MISCIssue TrackingThird Party Advisory
git.kernel.org/pub/…X Refsource MISCMailing ListPatchVendor Advisory
git.kernel.org/pub/…X Refsource MISCMailing ListPatchVendor Advisory
git.kernel.org/pub/…X Refsource MISCMailing ListPatchVendor Advisory
git.kernel.org/pub/…X Refsource MISCMailing ListPatchVendor Advisory
lists.debian.org/debian-lts-announce/2022/03/msg00012.htmlMailing ListX Refsource MLISTThird Party Advisory
www.debian.org/security/2022/dsa-5096Vendor AdvisoryX Refsource DEBIANThird Party Advisory
www.oracle.com/security-alerts/cpujul2022.htmlX Refsource MISCThird Party Advisory
security.netapp.com/advisory/ntap-20220303-0002/X Refsource CONFIRMThird Party Advisory
www.suse.com/support/update/announcement/2021/suse-su-20214057-1/Advisory

Show all 18 references

bugzilla.suse.com/1191813REPORT
www.suse.com/security/cve/CVE-2021-20322WEB
www.suse.com/support/update/announcement/2021/suse-su-20214075-1/Advisory
ubuntu.com/security/CVE-2021-20322REPORT
ubuntu.com/security/notices/USN-5268-1Advisory
www.cve.org/CVERecord?id=CVE-2021-20322REPORT
security-tracker.debian.org/tracker/CVE-2021-20322Advisory
nvd.nist.gov/vuln/detail/CVE-2021-20322OvalAdvisory