Security readout for executives and security teams
CVE-2021-22555 is a Linux kernel memory corruption flaw in Netfilter. A local attacker may use it to gain higher privileges or crash the system. Because CISA lists it in KEV and public exploit references exist, exposed Linux systems should be treated as urgent patch targets. Linux hosts using affected kernels are the primary exposure. Risk is higher on systems allowing untrusted local users, container workloads, or user namespace access. NetApp published an advisory, so appliance and vendor-managed Linux derivatives also require vendor-specific checks. Treat as high priority remediation. This is not just a theoretical kernel bug: CISA KEV indicates exploitation, and successful abuse can grant high-impact privileges on affected Linux systems. Mitigation focus: Apply vendor kernel updates that include the upstream x_tables fixes.; Use supported kernel live patches where vendor guidance names CVE-2021-22555.; Check distribution, appliance, and cloud image advisories for fixed kernel versions..
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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Open ATT&CK lookupCVE-2021-22555 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.3 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H1.66Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.3HighVector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528CVE reference · x_refsource_MISC
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21CVE reference · x_refsource_MISC
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801dCVE reference · x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20210805-0010/CVE reference · x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22555CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.