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CVE-2021-47166· NVD / CVE Program· CNA Linux

NFS: Don't corrupt the value of pg_bytes_written in nfs_do_recoalesce()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.23% (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 0d0ea309357dea0d85a82815f02157eb7fcda39f, 2fe1cac336b55a1f79e603e9ce3552c3623e90eb, 40f139a6d50c232c0d1fd1c5e65a845c62db0ede.

Low priority for now. Upgrade to Linux Linux 0d0ea309357dea0d85a82815f02157eb7fcda39f, 2fe1cac336b55a1f79e603e9ce3552c3623e90eb, 40f139a6d50c232c0d1fd1c5e65a845c62db0ede 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: NFS: Don't corrupt the value of pg_bytes_written in nfs_do_recoalesce() The value of mirror->pg_bytes_written should only be updated after a successful attempt to flush out the requests on the list.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 25, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 14th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 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-2021-47166

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 kernel4.0 and later · before 4.4.271
  • linux linux kernel4.5 and later · before 4.9.271
  • linux linux kernel4.10 and later · before 4.14.235
  • linux linux kernel4.15 and later · before 4.19.193
  • linux linux kernel4.20 and later · before 5.4.124
  • linux linux kernel5.5 and later · before 5.10.42
  • linux linux kernel5.11 and later · before 5.12.9
  • linux linux kernel5.13

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

    • 4.0affected
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before e8b8418ce14ae66ee55179901edd12191ab06a9eaffected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before b291baae24f876acd5a5dd57d0bb2bbac8a68b0caffected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before c757c1f1e65d89429db1409429436cf40d47c008affected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before 40f139a6d50c232c0d1fd1c5e65a845c62db0edeaffected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before 785917316b25685c9b3a2a88f933139f2de75e33affected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before 7087db95c0a06ab201b8ebfac6a7ec1e34257997affected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before 2fe1cac336b55a1f79e603e9ce3552c3623e90ebaffected · git
    • a7d42ddb3099727f58366fa006f850a219cce6c8 and later · before 0d0ea309357dea0d85a82815f02157eb7fcda39faffected · git
    • before 4.0not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 5.14.6-15.14.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • 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
  • CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV
    83Now
  • CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV
    77This week
  • CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV
    77This week
  • CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV
    77This week

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 Linux0d0ea309357dea0d85a82815f02157eb7fcda39fVendor (CNA)
Linux Linux2fe1cac336b55a1f79e603e9ce3552c3623e90ebVendor (CNA)
Linux Linux40f139a6d50c232c0d1fd1c5e65a845c62db0edeVendor (CNA)
Linux Linux7087db95c0a06ab201b8ebfac6a7ec1e34257997Vendor (CNA)
Linux Linux785917316b25685c9b3a2a88f933139f2de75e33Vendor (CNA)
Linux Linuxb291baae24f876acd5a5dd57d0bb2bbac8a68b0cVendor (CNA)
Linux Linuxc757c1f1e65d89429db1409429436cf40d47c008Vendor (CNA)
Linux Linuxe8b8418ce14ae66ee55179901edd12191ab06a9eVendor (CNA)
debian:linux5.14.6-1 · 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).

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
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
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:N/I:N/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 (7 more)

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

All records