CVE-2024-40913· NVD / CVE Program· CNA Linux

cachefiles: defer exposing anon_fd until after copy_to_user() succeeds

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: 0.28% (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 4b4391e77a6bf24cba2ef1590e113d9b73b11039, b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32, d2d3eb377a5d081bf2bed177d354a4f59b74da88.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 4b4391e77a6bf24cba2ef1590e113d9b73b11039, b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32, d2d3eb377a5d081bf2bed177d354a4f59b74da88 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: cachefiles: defer exposing anon_fd until after copy_to_user() succeeds After installing the anonymous fd, we can now see it in userland and close it. However, at this point we may not have gotten the reference count of the cache, but we will put it during colse fd, so this may cause a cache UAF. So grab the cache reference count before fd_install(). In addition, by kernel convention, fd is taken over by the user land after fd_install(), and the kernel should not call close_fd() after that, i.e., it should call fd_install() after everything is ready, thus fd_install() is called after copy_to_user() succeeds.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2024-11407

Published: Jul 12, 2024
Updated: Jun 17, 2026
EPSS: 0.2% · 20th percentile
CWE: CWE-416

Report tools

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Action score

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

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

linux linux kernel5.19 and later · before 6.1.95
linux linux kernel6.2 and later · before 6.6.35
linux linux kernel6.7 and later · before 6.9.6
linux linux kernel6.10

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
- 5.19affected
- c8383054506c77b814489c09877b5db83fd4abf2 and later · before eac51d9daacd61dcc93333ff6a890cf3efc8c1c0affected · git
- c8383054506c77b814489c09877b5db83fd4abf2 and later · before d2d3eb377a5d081bf2bed177d354a4f59b74da88affected · git
- c8383054506c77b814489c09877b5db83fd4abf2 and later · before b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32affected · git
- c8383054506c77b814489c09877b5db83fd4abf2 and later · before 4b4391e77a6bf24cba2ef1590e113d9b73b11039affected · git
- before 5.19not affected · semver
- 6.1.95 and later · up to and including 6.1.*not affected · semver
- 6.6.35 and later · up to and including 6.6.*not affected · semver
- 6.9.6 and later · up to and including 6.9.*not affected · semver
- 6.10 and laternot affected · original_commit_for_fix

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.99-1	6.1.99-1
Debian:13	linux	before 6.9.7-1	6.9.7-1

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

Published before and after this one in the same product

← EarlierCVE-2024-40910Jul 12, 2024 · ax25: Fix refcount imbalance on inbound connections
22Monitor
← EarlierCVE-2024-40911Jul 12, 2024 · wifi: cfg80211: Lock wiphy in cfg80211_get_station
22Monitor
Later →CVE-2024-40914Jul 12, 2024 · mm/huge_memory: don't unpoison huge_zero_folio
22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	4b4391e77a6bf24cba2ef1590e113d9b73b11039	Vendor (CNA)
Linux Linux	b9f58cdae6a364a3270fd6b6a46e0fd4f7f8ce32	Vendor (CNA)
Linux Linux	d2d3eb377a5d081bf2bed177d354a4f59b74da88	Vendor (CNA)
Linux Linux	eac51d9daacd61dcc93333ff6a890cf3efc8c1c0	Vendor (CNA)
debian:linux	6.1.99-1 · Debian:12	Package 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.

TR-24-0942 · Jul 16, 2024(Linux Kernel Güncellemesi)

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-416 · Use After Free

CVSS vector

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

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

Fix✗ → ✓Sep 28, 2026, 10:08 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/4b4391e77a6bf24cba2ef1590e113d9b73b11039

Show all references (4 more)

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

All records