CVE-2021-20322: A flaw in the processing of received ICMP errors (ICMP fragment needed and ICMP redirect) in the Linux kernel functionality was found to all
Noroxi assessment
Priority: Monitor (action score 31/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 6.9% (FIRST EPSS); higher than 94.1% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: bpftool (AlmaLinux:8) 4.18.0-372.9.1.el8; kernel (AlmaLinux:8) 4.18.0-372.9.1.el8; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-372.9.1.el8.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to bpftool (AlmaLinux:8) 4.18.0-372.9.1.el8; kernel (AlmaLinux:8) 4.18.0-372.9.1.el8; kernel-abi-stablelists (AlmaLinux:8) 4.18.0-372.9.1.el8 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
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.
- BDU:2022-03142
- ALSA-2022:1988
- DLA-2843-1
- DLA-2941-1
- DSA-5096-1
- openSUSE-SU-2021:1501-1
- openSUSE-SU-2021:3806-1
- openSUSE-SU-2021:3876-1
- openSUSE-SU-2021:3941-1
- RHSA-2022:1975
- RHSA-2022:1988
- RHSA-2022:4829
- RHSA-2022:4835
- RLSA-2022:1975
- RLSA-2022:1988
- SUSE-SU-2021:3806-1
- SUSE-SU-2021:3807-1
- SUSE-SU-2021:3848-1
- SUSE-SU-2021:3876-1
- SUSE-SU-2021:3877-1
- Published
- Feb 18, 2022
- Updated
- Jul 30, 2026
- EPSS
- 6.9% · 94th percentile
- CWE
- CWE-330
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 29 / 40 · 7.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 2 / 30 · 6.9%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| netapp | active iq unified manager | cpe:2.3:a:netapp:active_iq_unified_manager |
| netapp | e-series santricity os controller | cpe:2.3:a:netapp:e-series_santricity_os_controller |
| netapp | solidfire\, enterprise sds \& hci storage node | cpe:2.3:a:netapp:solidfire\,_enterprise_sds_\&_hci_storage_node |
| netapp | solidfire \& hci management node | cpe:2.3:a:netapp:solidfire_\&_hci_management_node |
| netapp | fas baseboard management controller firmware | cpe:2.3:o:netapp:fas_baseboard_management_controller_firmware |
| netapp | fas baseboard management controller | cpe:2.3:h:netapp:fas_baseboard_management_controller |
| netapp | aff baseboard management controller firmware | cpe:2.3:o:netapp:aff_baseboard_management_controller_firmware |
| netapp | aff baseboard management controller | cpe:2.3:h:netapp:aff_baseboard_management_controller |
| netapp | aff a700s firmware | cpe:2.3:o:netapp:aff_a700s_firmware |
and 20 more
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- debian debian linux9.0
- fedoraproject fedora34
- linux linux kernel5.11 and later · before 5.13.14
- linux linux kernel4.15 and later · before 4.19.215
- linux linux kernel4.20 and later · before 5.4.157
- linux linux kernel5.5 and later · before 5.10.62
- netapp active iq unified managerall versions
- netapp aff a700s firmwareall versions
- netapp aff baseboard management controller firmwareall versions
- netapp e-series santricity os controller11.0 and later · up to 11.70.1 inclusive
- netapp fas baseboard management controller firmwareall versions
- netapp h300e firmwareall versions
- netapp h300s firmwareall versions
- netapp h410s firmwareall versions
- netapp h500e firmwareall versions
- netapp h500s firmwareall versions
- netapp h700e firmwareall versions
- netapp h700s firmwareall versions
- netapp hci compute node firmwareall versions
Versions reported by the vendor
Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.
n/a kernel
- 4.15 and later · before 4.19.215affected
- 4.20 and later · before 5.4.146affected
- 5.5 and later · before 5.10.65affected
- 5.11 and later · before 5.13.17affected
- 5.14 and later · before 5.14.4affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bpftool | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-core | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-tools | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-tools-libs | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | kernel-tools-libs-devel | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | perf | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| AlmaLinux:8 | python3-perf | before 4.18.0-372.9.1.el8 | 4.18.0-372.9.1.el8 |
| Debian:10 | linux | before 4.19.232-1 | 4.19.232-1 |
| Debian:12 | linux | before 5.14.6-1 | 5.14.6-1 |
| Debian:9 | linux | before 4.9.290-1 | 4.9.290-1 |
| Debian:9 | linux-4.19 | before 4.19.232-1~deb9u1 | 4.19.232-1~deb9u1 |
+96
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV90Now
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
Published before and after this one in the same product
- ← EarlierCVE-2022-25265Feb 16, 2022 · In the Linux kernel through 5.16.10, certain binary files may have the exec-all attribute if they were built in approximately 2003 (e.g., wi31Monitor
- ← EarlierCVE-2021-20321Feb 18, 2022 · A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users do rename in specific way with Ove18Monitor
- Later →CVE-2021-4093Feb 18, 2022 · A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES).35Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:bpftool | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-abi-stablelists | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-core | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-cross-headers | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-core | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-devel | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-debug-modules-extra | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-devel | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-doc | 4.18.0-372.9.1.el8 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 5.14.6-1 · Debian:12 | Package registry (OSV) |
| debian:linux-4.19 | 4.19.232-1~deb9u1 · Debian:9 | Package registry (OSV) |
| opensuse:kernel-azure | 5.3.18-38.31.1 · openSUSE:Leap 15.3 | Package registry (OSV) |
| opensuse:kernel-debug | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-default | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-default-base | 5.3.18-lp152.106.1.lp152.8.52.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-docs | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-kvmsmall | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-obs-build | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-obs-qa | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-preempt | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-source | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:kernel-source-azure | 5.3.18-38.31.1 · openSUSE:Leap 15.3 | Package registry (OSV) |
| opensuse:kernel-syms | 5.3.18-lp152.106.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| red hat:kernel-rt | 0:4.18.0-372.9.1.rt7.166.el8 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-core | 0:4.18.0-372.9.1.rt7.166.el8 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug | 0:4.18.0-372.9.1.rt7.166.el8 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-core | 0:4.18.0-372.9.1.rt7.166.el8 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
+22
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-22-0474 · Jul 4, 2022(RedHat Güvenlik Güncellemesi)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-330 · Use of Insufficiently Random ValuesCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (8 more)Show less
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv4/route.c?h=v5.15-rc6&id=67d6d681e15b578c1725bad8ad079e05d1c48a8e
- git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv6/route.c?h=v5.15-rc6&id=a00df2caffed3883c341d5685f830434312e4a43
- lists.debian.org/debian-lts-announce/2022/03/msg00012.html
- security.netapp.com/advisory/ntap-20220303-0002/
- www.debian.org/security/2022/dsa-5096
- www.oracle.com/security-alerts/cpujul2022.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.