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Review reviewHigh

CVE-2025-39985

Linux

In the Linux kernel, the following vulnerability has been resolved: can: mcba_usb: populate ndo_change_mtu() to prevent buffer overflow Sending an PF_PACKET allows to bypass the CAN framework logic and to directly reach the xmit() function of a CAN driver. The only check which is performed by the PF_PACKET framework is to make sure that skb->len fits the interface's MTU. Unfortunately, because the mcba_usb driver does not populate its net_device_ops->ndo_change_mtu(), it is possible for an attacker to configure an invalid MTU by doing, for example: $ ip link set can0 mtu 9999 After doing so...

CVSS
7.8
EPSS
0.16%
6.07% percentile
CISA KEV
Not listed
Published
2025.10.15
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.16%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: can: mcba_usb: populate ndo_change_mtu() to prevent buffer overflow Sending an PF_PACKET allows to bypass the CAN framework logic and to directly reach the xmit() function of a CAN driver. The only check which is performed by the PF_PACKET framework is to make sure that skb->len fits the interface's MTU. Unfortunately, because the mcba_usb driver does not populate its net_device_ops->ndo_change_mtu(), it is possible for an attacker to configure an invalid MTU by doing, for example: $ ip link set can0 mtu 9999 After doing so...

Affected product and versions

Product
Linux
Affected versions
>= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 0fa9303c4b9493727e0d3a6ac3729300e3013930, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 37aed407496bf6de8910e588edb04d2435fa7011, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 6eec67bfb25637f9b51e584cf59ddace59925bc8, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < ca4e51359608e1f29bf1f2c33c3ddf775b6b7ed1, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 3664ae91b26d1fd7e4cee9cde17301361f4c89d5, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 6b9fb82df8868dbe9ffea5874b8d35f951faedbb, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < b638c3fb0f163e69785ceddb3b434a9437878bec, >= 51f3baad7de943780ce0c17bd7975df567dd6e14 < 17c8d794527f01def0d1c8b7dc2d7b8d34fed0e6, >= 4.12
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available
CVE-2025-39985 — Linux | SECUFOCUS NOW