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NVD / CVE Program· CNA Linux

CVE-2021-47477: comedi: dt9812: fix DMA buffers on stack

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: 0.72% (FIRST EPSS); higher than 53.7% of all records.
  • 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 20cebb8b620dc987e55ddc46801de986e081757e, 365a346cda82f51d835c49136a00a9df8a78c7f2, 39ea61037ae78f14fa121228dd962ea3280eacf3.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 20cebb8b620dc987e55ddc46801de986e081757e, 365a346cda82f51d835c49136a00a9df8a78c7f2, 39ea61037ae78f14fa121228dd962ea3280eacf3 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: dt9812: fix DMA buffers on stack USB transfer buffers are typically mapped for DMA and must not be allocated on the stack or transfers will fail. Allocate proper transfer buffers in the various command helpers and return an error on short transfers instead of acting on random stack data. Note that this also fixes a stack info leak on systems where DMA is not used as 32 bytes are always sent to the device regardless of how short the command is.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 22, 2024
Updated
Jun 17, 2026
EPSS
0.7% · 53th 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 · 0.7%

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-2021-47477

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 kernel2.6.29 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

    • 2.6.29affected
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before a6af69768d5cb4b2528946d53be5fa19ade37723affected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 365a346cda82f51d835c49136a00a9df8a78c7f2affected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 8a52bc480992c7c9da3ebfea456af731f50a4b97affected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 39ea61037ae78f14fa121228dd962ea3280eacf3affected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 3efb7af8ac437085b6c776e5b54830b149d86efeaffected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 786f5b03450454557ff858a8bead5d7c0cbf78d6affected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 3ac273d154d634e2034508a14db82a95d7ad12edaffected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 20cebb8b620dc987e55ddc46801de986e081757eaffected · git
    • 63274cd7d38a3322d90b66a5bc976de1fb899051 and later · before 536de747bc48262225889a533db6650731ab25d3affected · 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-2021-47475May 22, 2024 · comedi: vmk80xx: fix transfer-buffer overflows
    31Monitor
  • ← EarlierCVE-2021-47476May 22, 2024 · comedi: ni_usb6501: fix NULL-deref in command paths
    18Monitor
  • Later →CVE-2021-47478May 22, 2024 · isofs: Fix out of bound access for corrupted isofs image
    36Monitor

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 Linux20cebb8b620dc987e55ddc46801de986e081757eVendor (CNA)
Linux Linux365a346cda82f51d835c49136a00a9df8a78c7f2Vendor (CNA)
Linux Linux39ea61037ae78f14fa121228dd962ea3280eacf3Vendor (CNA)
Linux Linux3ac273d154d634e2034508a14db82a95d7ad12edVendor (CNA)
Linux Linux3efb7af8ac437085b6c776e5b54830b149d86efeVendor (CNA)
Linux Linux536de747bc48262225889a533db6650731ab25d3Vendor (CNA)
Linux Linux786f5b03450454557ff858a8bead5d7c0cbf78d6Vendor (CNA)
Linux Linux8a52bc480992c7c9da3ebfea456af731f50a4b97Vendor (CNA)
Linux Linuxa6af69768d5cb4b2528946d53be5fa19ade37723Vendor (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