What’s Vulnerable › Vulnerabilities
CVE-2021-20322
- Severity: high (CVSS 7.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 6.9% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2022-02-18 · updated 2026-07-30
- Weakness: CWE-330
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.
Affected products
- Debian Linux: 9.0, 10.0
- Fedoraproject Fedora: 34
- Linux kernel: from 4.15 before 4.19.215; from 4.20 before 5.4.157; from 5.5 before 5.10.62; from 5.11 before 5.13.14 — fixed in 4.19.215, 5.10.62, 5.13.14, 5.4.157
- Active IQ Unified Manager for VMware vSphere, Linux, and Microsoft Windows: all versions
- NetApp Aff A700S Firmware: all versions
- NetApp Aff Baseboard Management Controller Firmware: all versions
- E-Series SANtricity OS Controller Software 11.x: from 11.0 through 11.70.1
- NetApp Fas Baseboard Management Controller Firmware: all versions
- NetApp H300E Firmware: all versions
- NetApp H300S Firmware: all versions
- NetApp H410S Firmware: all versions
- NetApp H500E Firmware: all versions
- NetApp H500S Firmware: all versions
- NetApp H700E Firmware: all versions
- NetApp H700S Firmware: all versions
- NetApp Hci Compute Node Firmware: all versions
- NetApp Solidfire, Enterprise Sds & Hci Storage Node: all versions
- NetApp Solidfire & Hci Management Node: all versions
- Oracle Communications Cloud Native Core Binding Support Function: 22.1.3
- Oracle Communications Cloud Native Core Network Exposure Function: 22.1.1
- Oracle Communications Cloud Native Core Policy: 22.2.0
How to fix
Upgrade to a fixed version: Linux kernel 4.19.215, 5.10.62, 5.13.14, 5.4.157. Check the vendor advisory for mitigations.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2014230
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv4/route.c?h=v5.15-rc6&id=67d6d681e15b578c1725bad8ad079e05d1c48a8e
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/ipv6/route.c?h=v5.15-rc6&id=a00df2caffed3883c341d5685f830434312e4a43
- https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
- https://security.netapp.com/advisory/ntap-20220303-0002/
- https://www.debian.org/security/2022/dsa-5096
- https://www.oracle.com/security-alerts/cpujul2022.html
- https://bugzilla.redhat.com/show_bug.cgi?id=2014230
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=4785305c05b25a242e5314cc821f54ade4c18810
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v5.15-rc6&id=6457378fe796815c973f631a1904e147d6ee33b1
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