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CVE Record

CVE-2025-40053: net: dlink: handle copy_thresh allocation failure

In the Linux kernel, the following vulnerability has been resolved: net: dlink: handle copy_thresh allocation failure The driver did not handle failure of `netdev_alloc_skb_ip_align()`. If the allocation failed, dereferencing `skb->protocol` could lead to a NULL pointer dereference. This patch tries to allocate `skb`. If the allocation fails, it falls back to the normal path. Tested-on: D-Link DGE-550T Rev-A3

HighCVSS 7.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux D-Link network driver can crash the system if a packet-buffer allocation fails and the driver uses the missing buffer. The result is loss of availability, not disclosed data theft or modification. Systems using the affected driver deserve prompt attention, especially where network uptime is important.

Executive priority

Treat as a high-priority availability issue for systems using the relevant driver, but not as an estate-wide Linux emergency without exposure confirmation. Identify affected hardware and active drivers first, then patch uptime-sensitive or externally reachable systems promptly.

Technical view

The driver failed to check whether netdev_alloc_skb_ip_align() returned NULL before accessing skb->protocol, allowing a NULL-pointer dereference. The Linux fix retries allocation and, if unsuccessful, falls back to the normal path. The issue has CVSS 3.1 score 7.5 for network-reachable denial of service.

Likely exposure

Exposure is limited to affected Linux kernels where the relevant D-Link network driver is present and active. The fix was tested on D-Link DGE-550T Rev-A3, but the bundle does not establish that this is the only applicable hardware. Exact version applicability should be confirmed against distribution kernel guidance and stable fixes.

Exploitation context

The CVSS vector describes unauthenticated, low-complexity, network-reachable availability impact. However, the supplied sources provide no evidence of public exploitation or active attacks, and the CVE is not listed as KEV. Practical triggering conditions beyond allocation failure are not established in the bundle.

Researcher notes

The documented failure is an unchecked allocation result followed by skb->protocol access. The remediation adds failure handling and a normal-path fallback. No confidentiality or integrity impact, exploit proof, or active exploitation is documented. The supplied affected-version data is difficult to interpret, so commit or distribution-level verification is preferable.

Mitigation direction

  • Update to a distribution-supported kernel containing the applicable stable Linux fix.
  • Prioritize internet-facing or availability-critical systems using the affected D-Link driver.
  • Check Linux distribution guidance for backported fixes and exact package versions.
  • Where updating is delayed, reduce exposure of affected network interfaces where operationally feasible.

Validation and detection

  • Inventory Linux systems and identify whether the relevant D-Link network driver is active.
  • Record kernel and distribution package versions on potentially exposed systems.
  • Confirm the installed kernel includes the applicable referenced stable commit or vendor backport.
  • After updating, verify the intended kernel is running and affected networking remains operational.
Prepared
Confidence
medium
Sources
9

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

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CVE-2025-40053 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.5 (3.1)
Known Exploited
No
Published

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

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
0ADP providers
8Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.5CVSS 3.1HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.5High
CVSS 3.1 vector shape for CVE-2025-40053Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2unaffected
LinuxLinux2.6.12, 0, 5.10.246, 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3, 6.18affected
Weakness

CWE details

No CWE listed

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