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CVE-2021-47464· NVD / CVE Program· CNA Linux

audit: fix possible null-pointer dereference in audit_filter_rules

Noroxi assessment

Priority: Monitor (action score 29/100)

  • 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: 0.22% (FIRST EPSS).
  • Someone with local access to the system 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: Linux Linux 16802fa4c33eb1a8efb23f1e93365190e4047d05, 4e9e46a700201b4c85081fd478c99c692a9aaa0d, 6e3ee990c90494561921c756481d0e2125d8b895.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 16802fa4c33eb1a8efb23f1e93365190e4047d05, 4e9e46a700201b4c85081fd478c99c692a9aaa0d, 6e3ee990c90494561921c756481d0e2125d8b895 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

In the Linux kernel, the following vulnerability has been resolved: audit: fix possible null-pointer dereference in audit_filter_rules Fix possible null-pointer dereference in audit_filter_rules. audit_filter_rules() error: we previously assumed 'ctx' could be null

HighCVSS 7.4 · v3.1—No exploit Fix available
Published
May 22, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 12th percentile

Report tools

JSON

Action score

29

Monitor

Low priority for now.

CVSS
29 / 40 · 7.4 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

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.

Follow CVE-2021-47464

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.3 and later · before 5.4.156
  • linux linux kernel5.5 and later · before 5.10.76
  • linux linux kernel5.11 and later · before 5.14.15
  • linux linux kernel5.15

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.3affected
    • bf361231c295d92a28ca283ea713f56e93e55796 and later · before d6f451f1f60c58d73038c7c3177066f8f084e2a2affected · git
    • bf361231c295d92a28ca283ea713f56e93e55796 and later · before 16802fa4c33eb1a8efb23f1e93365190e4047d05affected · git
    • bf361231c295d92a28ca283ea713f56e93e55796 and later · before 4e9e46a700201b4c85081fd478c99c692a9aaa0daffected · git
    • bf361231c295d92a28ca283ea713f56e93e55796 and later · before 6e3ee990c90494561921c756481d0e2125d8b895affected · git
    • before 5.3not affected · semver
    • 5.4.156 and later · up to and including 5.4.*not affected · semver
    • 5.10.76 and later · up to and including 5.10.*not affected · semver
    • 5.14.15 and later · up to and including 5.14.*not affected · semver
    • 5.15 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.14.16-15.14.16-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • 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 KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now

Published before and after this one in the same product

  • ← EarlierCVE-2021-47462May 22, 2024 · mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL in mbind()
    22Monitor
  • ← EarlierCVE-2021-47463May 22, 2024 · mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()
    22Monitor
  • Later →CVE-2021-47465May 22, 2024 · KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux16802fa4c33eb1a8efb23f1e93365190e4047d05Vendor (CNA)
Linux Linux4e9e46a700201b4c85081fd478c99c692a9aaa0dVendor (CNA)
Linux Linux6e3ee990c90494561921c756481d0e2125d8b895Vendor (CNA)
Linux Linuxd6f451f1f60c58d73038c7c3177066f8f084e2a2Vendor (CNA)
debian:linux5.14.16-1 · Debian:12Package registry (OSV)

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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, 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.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system 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
high · the service can be disrupted
Attack vector
Local
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (3 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records