What is CVE-2023-21420?

CVE-2023-21420 is a high-severity vulnerability in Samsung Android, classified under Use of Externally-Controlled Format String. CVSS score: 7.3/10. Published 2023-02-09.

How severe is CVE-2023-21420?

High severity. CVSS v3 base score is 7.3 out of 10.

Vulnerability in Samsung Android

CVE-2023-21420

Use of Externally-Controlled Format String vulnerabilities in STST TA prior to SMR Jan-2023 Release 1 allows arbitrary code execution.

Published 2023-02-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.4th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Samsung Android — versions 10.0, 11.0
Samsung Mobile Devices — versions Q(10), R(11) devices with Teegris

Weakness classification (CWE)

CWE-134 — Use of Externally-Controlled Format String

References

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

Frequently asked questions

What is CVE-2023-21420?: CVE-2023-21420 is a high-severity vulnerability in Samsung Android, classified under Use of Externally-Controlled Format String. CVSS score: 7.3/10. Published 2023-02-09.
How severe is CVE-2023-21420?: High severity. CVSS v3 base score is 7.3 out of 10.