CVE-2021-0320

Local key disclosure via unsynchronized lock state

Published Jan 11, 2021 · Updated Aug 3, 2024

Information disclosure in Android 10 and 11 allows local users to access keyguard-bound keys by winning a lock-state race. The is_device_locked and set_device_locked functions access mIsDeviceLockedForUser without synchronization, allowing an inconsistent lock state to bypass lockscreen requirements. Low-privileged local access and precise timing are required; user interaction is not required, and the documented impact is limited to protected-key disclosure.

CVSS severity4.7
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Android 10 and 11 allows local users to access keyguard-bound keys by winning a lock-state race. The is_device_locked and set_device_locked functions access mIsDeviceLockedForUser without synchronization, allowing an inconsistent lock state to bypass lockscreen requirements. Low-privileged local access and precise timing are required; user interaction is not required, and the documented impact is limited to protected-key disclosure.

The record

CVE
CVE-2021-0320
Published
Jan 11, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-362, CAPEC-29, CAPEC-26
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jan 11, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

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

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Androidversion=Android-10; version=Android-11

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
1.9NIST NVDAV:L/AC:M/Au:N/C:P/I:N/A:N

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-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CAPEC-29Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
CAPEC-26Leveraging Race Conditions

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

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Your stack

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