How severe is CVE-2021-45402?

CVE-2021-45402 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 high, integrity none, and availability none.

Is CVE-2021-45402 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45402?

CVE-2021-45402 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-45402?

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

When was CVE-2021-45402 published?

CVE-2021-45402 was published on 2022-02-11 and last updated on 2026-06-17.

CVE-2021-45402

CVE-2021-45402 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-668.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-668
Affected product: Linux Linux Kernel
Published: 2022-02-11
Last modified: 2026-06-17

Description

The check_alu_op() function in kernel/bpf/verifier.c in the Linux kernel through v5.16-rc5 did not properly update bounds while handling the mov32 instruction, which allows local users to obtain potentially sensitive address information, aka a "pointer leak."

Frequently asked questions

What is CVE-2021-45402?: The check_alu_op() function in kernel/bpf/verifier.c in the Linux kernel through v5.16-rc5 did not properly update bounds while handling the mov32 instruction, which allows local users to obtain potentially sensitive address information, aka a "pointer leak."
How severe is CVE-2021-45402?: CVE-2021-45402 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 high, integrity none, and availability none.
Is CVE-2021-45402 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45402?: CVE-2021-45402 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-45402?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-45402 published?: CVE-2021-45402 was published on 2022-02-11 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*

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