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NVD / CVE Program· CNA Linux

CVE-2025-21744: wifi: brcmfmac: fix NULL pointer dereference in brcmf_txfinalize()

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: 0.25% (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 2326e19190e176fd72bb542b837a9d2b7fcb8693, 3877fc67bd3d5566cc12763bce39710ceb74a97d, 4.8; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.78.1-3; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.78.1-3.

Low priority for now. Upgrade to Linux Linux 2326e19190e176fd72bb542b837a9d2b7fcb8693, 3877fc67bd3d5566cc12763bce39710ceb74a97d, 4.8; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.78.1-3; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.78.1-3 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: wifi: brcmfmac: fix NULL pointer dereference in brcmf_txfinalize() On removal of the device or unloading of the kernel module a potential NULL pointer dereference occurs. The following sequence deletes the interface: brcmf_detach() brcmf_remove_interface() brcmf_del_if() Inside the brcmf_del_if() function the drvr->if2bss[ifidx] is updated to BRCMF_BSSIDX_INVALID (-1) if the bsscfgidx matches. After brcmf_remove_interface() call the brcmf_proto_detach() function is called providing the following sequence: brcmf_detach() brcmf_proto_detach() brcmf_proto_msgbuf_detach() brcmf_flowring_detach() brcmf_msgbuf_delete_flowring() brcmf_msgbuf_remove_flowring() brcmf_flowring_delete() brcmf_get_ifp() brcmf_txfinalize() Since brcmf_get_ip() can and actually will return NULL in this case the call to brcmf_txfinalize() will result in a NULL pointer dereference inside brcmf_txfinalize() when trying to update ifp->ndev->stats.tx_errors. This will only happen if a flowring still has an skb. Although the NULL pointer dereference has only been seen when trying to update the tx statistic, all other uses of the ifp pointer have been guarded as well with an early return if ifp is NULL.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 27, 2025
Updated
Nov 5, 2026
EPSS
0.2% · 17th 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.

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When you'll hear from us

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  • 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 kernelbefore 6.1.129
  • linux linux kernel6.2 and later · before 6.6.78
  • linux linux kernel6.7 and later · before 6.12.14
  • linux linux kernel6.13 and later · before 6.13.3

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

    • 6faa698c35a43b9e74ea24e90fe37471d08d00d0, 9119232cc92a269d7860b4aa51f07d3923a3cc10, 4.9affected
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 2326e19190e176fd72bb542b837a9d2b7fcb8693affected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 59ff4fa653ff6db07c61152516ffba79c2a74bdaaffected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 61541d9b5a23df33934fcc620a3a81f246b1b240affected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 4e51d6d093e763348916e69d06d87e0a5593661baffected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 3877fc67bd3d5566cc12763bce39710ceb74a97daffected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before fbbfef2a5b858eab55741a58b2ac9a0cc8d53c58affected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before a2beefc4fa49ebc22e664dc6b39dbd054f8488f9affected · git
    • 7f00ee2bbc630900ba16fc2690473f3e2db0e264 and later · before 68abd0c4ebf24cd499841a488b97a6873d5efabbaffected · git
    • 4.7.10 and later · before 4.8affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.129-16.1.129-1
Debian:13linuxbefore 6.12.15-16.12.15-1

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-2025-21735Feb 27, 2025 · NFC: nci: Add bounds checking in nci_hci_create_pipe()
    31Monitor
  • ← EarlierCVE-2025-21738Feb 27, 2025 · ata: libata-sff: Ensure that we cannot write outside the allocated buffer
    22Monitor
  • Later →CVE-2025-21745Feb 27, 2025 · blk-cgroup: Fix class @block_class's subsystem refcount leakage
    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 / packageFixed versionSource
Linux Linux2326e19190e176fd72bb542b837a9d2b7fcb8693Vendor (CNA)
Linux Linux3877fc67bd3d5566cc12763bce39710ceb74a97dVendor (CNA)
Linux Linux4.8Vendor (CNA)
Linux Linux4.9Vendor (CNA)
Linux Linux4e51d6d093e763348916e69d06d87e0a5593661bVendor (CNA)
Linux Linux59ff4fa653ff6db07c61152516ffba79c2a74bdaVendor (CNA)
Linux Linux61541d9b5a23df33934fcc620a3a81f246b1b240Vendor (CNA)
Linux Linux68abd0c4ebf24cd499841a488b97a6873d5efabbVendor (CNA)
Linux Linuxa2beefc4fa49ebc22e664dc6b39dbd054f8488f9Vendor (CNA)
Linux Linuxfbbfef2a5b858eab55741a58b2ac9a0cc8d53c58Vendor (CNA)
azl3 kernel 6.6.64.2-9 on Azure Linux 3.06.6.78.1-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.78.1-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.179.1-1 on CBL Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL Mariner 2.0CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL-Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.129-1 · 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.

No history yet (it accumulates with the daily EPSS job).

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-476 · NULL Pointer Dereference

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. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (11 more)

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

All records