CVE-2021-39707

Unauthorized phone calls via unsafe intent resolution

Published Mar 16, 2022 · Updated Aug 4, 2024

Confused-deputy flaw in Android 10 through 12 allows local users to start phone calls without the CALL_PRIVILEGED permission. AppRestrictionsFragment.onReceive treated a restrictions intent as safe when it resolved to multiple activities instead of requiring the resolved activity to belong to the current package. A local app with no additional execution privileges can trigger the launch without user interaction, but the reported consequence is limited to unauthorized calls.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Confused-deputy flaw in Android 10 through 12 allows local users to start phone calls without the CALL_PRIVILEGED permission. AppRestrictionsFragment.onReceive treated a restrictions intent as safe when it resolved to multiple activities instead of requiring the resolved activity to belong to the current package. A local app with no additional execution privileges can trigger the launch without user interaction, but the reported consequence is limited to unauthorized calls.

The record

CVE
CVE-2021-39707
Published
Mar 16, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-610, T1068
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Mar 16, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Android-10 Android-11 Android-12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Androidversion=Android-10 Android-11 Android-12

Published CVSS scores

7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST National Vulnerability DatabaseAV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-610Externally Controlled Reference to a Resource in Another Sphere
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo