How severe is CVE-2023-21402?

CVE-2023-21402 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-21402 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-21402?

CVE-2023-21402 affects Google Android. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-21402?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-21402 published?

CVE-2023-21402 was published on 2023-12-04 and last updated on 2026-06-17.

CVE-2023-21402

CVE-2023-21402 is a critical-severity vulnerability in Google Android with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Google Android
Published: 2023-12-04
Last modified: 2026-06-17

Description

In MMU_UnmapPages of mmu_common.c, there is a possible out of bounds read due to improper input validation. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.

Frequently asked questions

What is CVE-2023-21402?: In MMU_UnmapPages of mmu_common.c, there is a possible out of bounds read due to improper input validation. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.
How severe is CVE-2023-21402?: CVE-2023-21402 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-21402 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-21402?: CVE-2023-21402 affects Google Android. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-21402?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-21402 published?: CVE-2023-21402 was published on 2023-12-04 and last updated on 2026-06-17.

References

https://source.android.com/security/bulletin/2023-12-01

Affected products (1)

cpe:2.3:o:google:android:-:*:*:*:*:*:*:*

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