What is CVE-2021-39658?

CVE-2021-39658 is a critical-severity vulnerability in Google Android, classified under Incorrect Default Permissions. CVSS score: 9.8/10. Published 2022-02-11.

How severe is CVE-2021-39658?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-39658 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Google Android

CVE-2021-39658

ismsEx service is a vendor service in unisoc equipment。ismsEx service is an extension of sms system service，but it does not check the permissions of the caller，resulting in permission leaks。Third-party apps can use this service to arbitrarily modify and set system properties。Product: AndroidVersions: Android SoCAndroid ID: A-207479207

Published 2022-02-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (45.3th percentile), scored 2026-10-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Google Android
Android — versions Android SoC

Weakness classification (CWE)

CWE-276 — Incorrect Default Permissions

Public proof-of-concept exploits

References

source.android.com/security/bulletin/2022-02-01 (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39658?: CVE-2021-39658 is a critical-severity vulnerability in Google Android, classified under Incorrect Default Permissions. CVSS score: 9.8/10. Published 2022-02-11.
How severe is CVE-2021-39658?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-39658 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.