CVE-2021-3679

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this weekElevated
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

A lack of CPU resource in the Linux kernel tracing module functionality in versions prior to 5.14-rc3 was found in the way user uses trace ring buffer in a specific way. Only privileged local users (with CAP_SYS_ADMIN capability) could use this flaw to starve the resources causing denial of service.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
50.6%
KEV
Not listed

Published

August 5, 2021

Last Modified

November 21, 2024

References (10)

Vendor Advisories for CVE-2021-3679(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(12)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-image-lowlatency (5.4.0.88.92) @ focal2026-05-26ubuntu
ubuntulinux-image-lowlatency (5.11.0.37.39) @ hirsute2026-05-26ubuntu
ubuntulinux-modules-5.11.0-1017-azure (5.11.0-1017.18) @ hirsute2026-05-26ubuntu
ubuntulinux-image-lowlatency (4.4.0.219.226) @ xenial2026-05-26ubuntu
ubuntulinux-tools-oem-20.04-edge (5.10.0.1050.52) @ focal2026-05-26ubuntu
ubuntulinux-oem-20.04c (5.13.0.1014.18) @ focal2026-05-26ubuntu
ubuntulinux-virtual-hwe-16.04-edge (4.15.0.159.152) @ xenial2026-05-26ubuntu
ubuntulinux-image-raspi2 (4.15.0.1096.94) @ bionic2026-05-26ubuntu
ubuntulinux-image-raspi2-hwe-18.04 (5.4.0.1044.79) @ focal2026-05-26ubuntu
ubuntulinux-image-lowlatency (4.4.0.222.229) @ xenial2026-05-26ubuntu
redhatkernel-rt-0:4.18.0-348.rt7.130.el82021-11-09redhat
redhatkernel-0:4.18.0-348.el82021-11-09redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(11)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 13× in last 7d / 50× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 107 total refreshes for this CVE.

  1. 2026-07-23 02:03 UTCEG score recompute
  2. 2026-07-22 22:49 UTCEG score recompute
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Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCaegistudio/RingBufferDetonator
    First seen Jul 20, 2021

    Exploitation for CVE-2021-3679 and document for its fix

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-3679?
CVE-2021-3679 is a medium vulnerability published on August 5, 2021. A lack of CPU resource in the Linux kernel tracing module functionality in versions prior to 5.14-rc3 was found in the way user uses trace ring buffer in a specific way. Only privileged local users (with CAPSYSADMIN capability) could use this flaw to starve the resources causing denial of service.
When was CVE-2021-3679 disclosed?
CVE-2021-3679 was first published in the National Vulnerability Database on August 5, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-3679 actively exploited?
CVE-2021-3679 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 50.6% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-3679?
CVE-2021-3679 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2021-3679?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3679, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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