What is CVE-2021-25518?

CVE-2021-25518 is a medium-severity vulnerability in Google Android, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.4/10. Published 2021-12-08.

How severe is CVE-2021-25518?

Medium severity. CVSS v3 base score is 6.4 out of 10.

Buffer overflow in Google Android

CVE-2021-25518

An improper boundary check in secure_log of LDFW and BL31 prior to SMR Dec-2021 Release 1 allows arbitrary memory write and code execution.

Vulnerability class: Buffer Overflow

Published 2021-12-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.4th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Google Android — versions 9.0, 10.0, 11.0
Samsung Mobile Devices — versions P(9.0), Q(10.0), R(11.0) devices with selected Exynos chipsets

Weakness classification (CWE)

References

security.samsungmobile.com/securityUpdate.smsb (Vendor Advisory)

Frequently asked questions

What is CVE-2021-25518?: CVE-2021-25518 is a medium-severity vulnerability in Google Android, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 6.4/10. Published 2021-12-08.
How severe is CVE-2021-25518?: Medium severity. CVSS v3 base score is 6.4 out of 10.