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NVD / CVE Program· CNA Linux

CVE-2021-47475: comedi: vmk80xx: fix transfer-buffer overflows

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 06ac746d57e6d32b062e220415c607b7e2e0fa50, 199acd8c110e3ae62833c24f632b0bb1c9f012a9, 278484ae93297b1bb1ce755f9d3b6d95a48c7d47.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 06ac746d57e6d32b062e220415c607b7e2e0fa50, 199acd8c110e3ae62833c24f632b0bb1c9f012a9, 278484ae93297b1bb1ce755f9d3b6d95a48c7d47 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 transfer-buffer overflows The driver uses endpoint-sized USB transfer buffers but up until recently had no sanity checks on the sizes. Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize of usb endpoints found") inadvertently fixed NULL-pointer dereferences when accessing the transfer buffers in case a malicious device has a zero wMaxPacketSize. Make sure to allocate buffers large enough to handle also the other accesses that are done without a size check (e.g. byte 18 in vmk80xx_cnt_insn_read() for the VMK8061_MODEL) to avoid writing beyond the buffers, for example, when doing descriptor fuzzing. The original driver was for a low-speed device with 8-byte buffers. Support was later added for a device that uses bulk transfers and is presumably a full-speed device with a maximum 64-byte wMaxPacketSize.

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-2021-47475

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 5229159f1d052821007aff1a1beb7873eacf1a9faffected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before ec85bcff4ed09260243d8f39faba99e1041718baaffected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 7a2021b896de1ad559d33b5c5cdd20b982242088affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 199acd8c110e3ae62833c24f632b0bb1c9f012a9affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 33d7a470730dfe7c9bfc8da84575cf2cedd60d00affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 278484ae93297b1bb1ce755f9d3b6d95a48c7d47affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before 06ac746d57e6d32b062e220415c607b7e2e0fa50affected · git
    • 985cafccbf9b7f862aa1c5ee566801e18b5161fb and later · before a23461c47482fc232ffc9b819539d1f837adf2b1affected · 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-2021-47473May 22, 2024 · scsi: qla2xxx: Fix a memory leak in an error path of qla2x00_process_els()
    22Monitor
  • ← EarlierCVE-2021-47474May 22, 2024 · comedi: vmk80xx: fix bulk-buffer overflow
    31Monitor
  • Later →CVE-2021-47476May 22, 2024 · comedi: ni_usb6501: fix NULL-deref in command paths
    18Monitor

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 Linux06ac746d57e6d32b062e220415c607b7e2e0fa50Vendor (CNA)
Linux Linux199acd8c110e3ae62833c24f632b0bb1c9f012a9Vendor (CNA)
Linux Linux278484ae93297b1bb1ce755f9d3b6d95a48c7d47Vendor (CNA)
Linux Linux33d7a470730dfe7c9bfc8da84575cf2cedd60d00Vendor (CNA)
Linux Linux40d2a7e278e2e7c0a5fd7e997e7eb63945bf93f7Vendor (CNA)
Linux Linux5229159f1d052821007aff1a1beb7873eacf1a9fVendor (CNA)
Linux Linux7a2021b896de1ad559d33b5c5cdd20b982242088Vendor (CNA)
Linux Linuxa23461c47482fc232ffc9b819539d1f837adf2b1Vendor (CNA)
Linux Linuxec85bcff4ed09260243d8f39faba99e1041718baVendor (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