Security readout for executives and security teams
Plain-English summary
CVE-2021-47464 is a Linux kernel flaw in the audit subsystem where certain rule filtering paths could hit a null pointer. The source rates it high because successful local exploitation could affect confidentiality, integrity, and availability, but the attack complexity is high and no active exploitation is cited.
Executive priority
Treat as a high-priority Linux kernel maintenance item, especially on shared infrastructure. There is no sourced evidence of active exploitation, so prioritize disciplined patch rollout over emergency response unless vendor advisories raise urgency.
Technical view
The issue is a CWE-476 null-pointer dereference in audit_filter_rules(). The CVSS vector is local, high complexity, no privileges required, no user interaction, unchanged scope, and high impact across confidentiality, integrity, and availability. Kernel stable commits are referenced as the resolution sources.
Likely exposure
Exposure is most relevant to Linux systems running affected kernel versions listed in the source bundle, including the 5.3, 5.4.156, 5.10.76, 5.14.15, and 5.15 ranges. Distribution backports may change exposure, so package-level vendor guidance is needed.
Exploitation context
The bundle does not cite KEV listing or confirmed active exploitation. The CVSS vector indicates a local attack path with high complexity and no required privileges, so internet-facing exposure is not the primary concern; shared hosts and systems allowing untrusted local execution deserve attention.
Researcher notes
The public description is sparse and centers on audit_filter_rules() assuming ctx handling incorrectly. The affected-version data is limited and should be interpreted through upstream commits and downstream vendor backports rather than raw upstream version strings alone.
Mitigation direction
- Apply vendor kernel updates that include the referenced Linux stable fixes.
- Check Linux distribution advisories for exact fixed package versions.
- Prioritize shared, multi-user, container-host, and untrusted workload systems.
- If patching is delayed, reduce untrusted local access where operationally feasible.
Validation and detection
- Inventory running kernel versions across Linux assets.
- Compare kernel packages against distribution advisories for CVE-2021-47464.
- Check kernel changelogs for the referenced stable commit identifiers.
- Confirm audit subsystem regression testing after kernel update.
Public sources used
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-476: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-47464 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
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/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.
SSVC decision data
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:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H1.45.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/d6f451f1f60c58d73038c7c3177066f8f084e2a2CVE reference, Linux
- https://git.kernel.org/stable/c/16802fa4c33eb1a8efb23f1e93365190e4047d05CVE reference, Linux
- https://git.kernel.org/stable/c/4e9e46a700201b4c85081fd478c99c692a9aaa0dCVE reference, Linux
- https://git.kernel.org/stable/c/6e3ee990c90494561921c756481d0e2125d8b895CVE reference, Linux
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.
NULL Pointer Dereference
NULL Pointer Dereference represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.