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NVD / CVE Program· CNA Linux

CVE-2021-47474: comedi: vmk80xx: fix bulk-buffer overflow

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.25% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 063f576c43d589a4c153554b681d32b3f8317c7b, 0866dcaa828c21bc2f94dac00e086078f11b5772, 1ae4715121a57bc6fa29fd992127b01907f2f993.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 063f576c43d589a4c153554b681d32b3f8317c7b, 0866dcaa828c21bc2f94dac00e086078f11b5772, 1ae4715121a57bc6fa29fd992127b01907f2f993 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: comedi: vmk80xx: fix bulk-buffer overflow The driver is using endpoint-sized buffers but must not assume that the tx and rx buffers are of equal size or a malicious device could overflow the slab-allocated receive buffer when doing bulk transfers.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 22, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 17th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

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-2021-47474

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 kernel2.6.31 and later · before 4.4.292
  • linux linux kernel4.5 and later · before 4.9.290
  • linux linux kernel4.10 and later · before 4.14.255
  • linux linux kernel4.15 and later · before 4.19.217
  • linux linux kernel4.20 and later · before 5.4.159
  • linux linux kernel5.5 and later · before 5.10.79
  • linux linux kernel5.11 and later · before 5.14.18
  • linux linux kernel5.15 and later · before 5.15.2

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

    • 2.6.31affected
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before e0e6a63fd97ad95fe05dfd77268a1952551e11a7affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 7cfb35db607760698d299fd1cf7402dfa8f09973affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 0866dcaa828c21bc2f94dac00e086078f11b5772affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 063f576c43d589a4c153554b681d32b3f8317c7baffected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 1ae4715121a57bc6fa29fd992127b01907f2f993affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before b7fd7f3387f070215e6be341e68eb5c087eeecc0affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 7b0e356189327287d0eb98ec081bd6dd97068cd3affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 47b4636ebdbeba2044b3db937c4d2b6a4fe3d0f2affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 78cdfd62bd54af615fba9e3ca1ba35de39d3871daffected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.15.3-15.15.3-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • 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

Published before and after this one in the same product

  • ← EarlierCVE-2021-47471May 22, 2024 · drm: mxsfb: Fix NULL pointer dereference crash on unload
    22Monitor
  • ← EarlierCVE-2021-47473May 22, 2024 · scsi: qla2xxx: Fix a memory leak in an error path of qla2x00_process_els()
    22Monitor
  • Later →CVE-2021-47475May 22, 2024 · comedi: vmk80xx: fix transfer-buffer overflows
    31Monitor

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 Linux063f576c43d589a4c153554b681d32b3f8317c7bVendor (CNA)
Linux Linux0866dcaa828c21bc2f94dac00e086078f11b5772Vendor (CNA)
Linux Linux1ae4715121a57bc6fa29fd992127b01907f2f993Vendor (CNA)
Linux Linux47b4636ebdbeba2044b3db937c4d2b6a4fe3d0f2Vendor (CNA)
Linux Linux78cdfd62bd54af615fba9e3ca1ba35de39d3871dVendor (CNA)
Linux Linux7b0e356189327287d0eb98ec081bd6dd97068cd3Vendor (CNA)
Linux Linux7cfb35db607760698d299fd1cf7402dfa8f09973Vendor (CNA)
Linux Linuxb7fd7f3387f070215e6be341e68eb5c087eeecc0Vendor (CNA)
Linux Linuxe0e6a63fd97ad95fe05dfd77268a1952551e11a7Vendor (CNA)
debian:linux5.15.3-1 · 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.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

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
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

nvd-primary

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 (8 more)

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

All records