CVE-2021-3679
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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…
rank 36 = 15 + 14 + 0 + 7 + 0
rank@v1 · scheduled
Someone is already using it
CISA KEV catalog · public proof-of-concept · FIRST EPSS
EPSS 0.00751 · without this subject the record ranks 21
What it costs you if it fires
NVD CVSS base score, then the CNA's own
CVSS 5.5, from NVD · without this subject the record ranks 22
It is getting worse, not staying still
FIRST EPSS series, rescorings and bad loads removed
no persisting rise in 365 days · without this subject the record ranks 36
How much of the world it touches
NVD CPE configurations
7 products in the CPE ranges · without this subject the record ranks 29
Someone else already set the date
CISA KEV remediation due date
no CISA due date · without this subject the record ranks 36
Hindsight · the state
Foresight · where to check next
This record is one instance of CWE-400, uncontrolled resource consumption. The index holds 3987 prior instances of this class, 8 KEV-listed. The nearest of its KEV-listed records are drawn beside this. taxonomy@v1
Running kernel? Check your version
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Harm, if it fires from the vector and the weakness
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CISA KEV & Federal Remediation Deadline from the record and CISA
The fix, and how long it's been waiting.
Show full BOD 26-04 deadline
CISA has not scored it, so the directive's own defaults apply: automatable no, technical impact total. Calendar days from the KEV listing or from when you find it on a system, whichever is first. Federal agencies are bound from 7 Dec 2026, and contracts often carry it to suppliers. The directive and its table
Exploit Status & Known PoCs a ladder, not a score
Current rung: Proof-of-concept published · 1 public repository, 2021-07-20.
- RUNG 1Nothing observed in held sources
- RUNG 2Proof-of-concept published · 1 public repository2021-07-20receipt
- RUNG 3Exploited in the wild · CISA KEV listed
- RUNG 4Ransomware campaign use known
Affected & Fixed Versions as published
Show all 7 published ranges
A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.
$22,900 = $4.99M incident cost x 0.6121449559255632 exposure x 0.00751 likelihood
udv@v1 · unaudited · wrong for you until you say what you run
$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.
What it is stated by the CNA
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. receipt
NVD's analysis a second authority
- severity
- 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- weakness
- CWE-400; CWE-835
- affected versions
- linux kernel < 5.14; linux kernel 5.14; linux kernel 5.14-rc1; and 4 more, listed in full below
check it yourself bugzilla.redhat.com git.kernel.org debian.org lists.debian.org lists.debian.org receipt
Movement the material steps
Show all 32 observations
32 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt
The pattern, elsewhere
This record is one instance of CWE-400, uncontrolled resource consumption. The index holds 3987 prior instances of this class, 8 KEV-listed. The nearest of its KEV-listed records are drawn beside this. cwe-consequences@4.20
"Matches n of m" counts the attributes the two records can both be compared on: the CVSS metrics they share a version of, any weakness class beyond this one, and the vendor. fit-rules@v1
3987 records in this class held. The six above are drawn from the ones CISA has listed as exploited, ranked by how much of the record matches this one. That is why every one of them is KEV-listed: the pool is, so the colour on those spokes says nothing the pool has not already said.
No curated product neighbourhood is held for this product, so the records above are the nearest this index can name. The neighbourhood table covers a small set of products and is extended by hand.
Siblings and hubs
Records related to this one
No record cites this identifier and it carries no alias. Its defect family is below.
Its defect family
kernel
Of the 6 records in this family that state one, this holds the highest EPSS percentile: 0.5197.
Grouped by shared product and weakness, not by shared vulnerability. Each record's own state is on its own page.
Family membership: held values
This record is one of a group, and the group's page describes all of them. This page is kept and dated, and the defect family's own page is the one we offer for indexing: the whole group.
Browse the index from here
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What usually comes next
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