CVE intelligence and bounded remediation

CVE-2021-20322 — Linux Linux Kernel security vulnerability

High CVSS 7.4

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.

Severity
High
CVSS
7.4 (3.1)
Published
2022-02-18
CISA KEV
Not currently listed
Ecosystem
linux/kernel
Weaknesses
CWE-330

Affected products

  • linux / linux_kernel
  • fedoraproject / fedora / 34
  • debian / debian_linux / 9.0
  • debian / debian_linux / 10.0
  • netapp / active_iq_unified_manager
  • netapp / e-series_santricity_os_controller

Showing 6 representative product identities from 23 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cryptography, certificate, signature, and channel validation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Inventory affected algorithms, key uses, trust stores, certificate validation settings, random sources, and plaintext channels across clients and services.
  • Determine which secrets, identities, signatures, or data protections depend on the affected primitive or validation path.
  • Check debug, compatibility, fallback, and hostname or audience override settings in build and runtime configuration.

Remediate safely

  • Use a maintained platform cryptographic API with approved algorithms, modes, parameters, randomness, and full peer identity validation.
  • Remove insecure fallback and validation bypasses; separate keys by purpose and load them from managed secret storage.
  • Plan rotation or reissuance for affected keys, certificates, tokens, hashes, or ciphertext and document compatibility sequencing.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.