How severe is CVE-2021-47416?

CVE-2021-47416 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-47416 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47416?

CVE-2021-47416 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-47416?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2021-47416 have an EU (EUVD) identifier?

Yes. CVE-2021-47416 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34421.

When was CVE-2021-47416 published?

CVE-2021-47416 was published on 2024-05-21 and last updated on 2026-06-17.

CVE-2021-47416

CVE-2021-47416 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-401.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (14th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-34421
Weakness: CWE-401
Affected product: Linux Linux Kernel
Published: 2024-05-21
Last modified: 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: phy: mdio: fix memory leak Syzbot reported memory leak in MDIO bus interface, the problem was in wrong state logic. MDIOBUS_ALLOCATED indicates 2 states: 1. Bus is only allocated 2. Bus allocated and __mdiobus_register() fails, but device_register() was called In case of device_register() has been called we should call put_device() to correctly free the memory allocated for this device, but mdiobus_free() calls just kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED _before_ calling device_register(), because put_device() should be called even in case of device_register() failure.

Frequently asked questions

What is CVE-2021-47416?: In the Linux kernel, the following vulnerability has been resolved: phy: mdio: fix memory leak Syzbot reported memory leak in MDIO bus interface, the problem was in wrong state logic. MDIOBUS_ALLOCATED indicates 2 states: 1. Bus is only allocated 2. Bus allocated and __mdiobus_register() fails, but device_register() was called In case of device_register() has been called we should call put_device() to correctly free the memory allocated for this device, but mdiobus_free() calls just kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED _before_ calling device_register(), because put_device() should be called even in case of device_register() failure.
How severe is CVE-2021-47416?: CVE-2021-47416 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47416 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (14th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47416?: CVE-2021-47416 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-47416?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2021-47416 have an EU (EUVD) identifier?: Yes. CVE-2021-47416 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34421.
When was CVE-2021-47416 published?: CVE-2021-47416 was published on 2024-05-21 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*

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