CVE-2021-0339

Local privilege escalation via unbounded transition animation

Published Feb 10, 2021 · Updated Aug 3, 2024

Privilege escalation in Android 8.1, 9, and 10 allows local users to keep malicious app content visible via a crafted transition animation. WindowContainer.loadAnimation accepted excessive durations or infinite repeat counts supplied through custom-animation APIs instead of enforcing a short maximum. Exploitation requires user interaction but no additional execution privileges, and the malicious content remains displayed as the target app enters the foreground.

CVSS severity7.8
High
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Android 8.1, 9, and 10 allows local users to keep malicious app content visible via a crafted transition animation. WindowContainer.loadAnimation accepted excessive durations or infinite repeat counts supplied through custom-animation APIs instead of enforcing a short maximum. Exploitation requires user interaction but no additional execution privileges, and the malicious content remains displayed as the target app enters the foreground.

The record

CVE
CVE-2021-0339
Published
Feb 10, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-754, T1404
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 10, 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 Android-8.1 Android-9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Google Cloud · Androidversion=Android-10 Android-8.1 Android-9

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NVDAV:N/AC:M/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-754Improper Check for Unusual or Exceptional Conditions
T1404Exploitation 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

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Your stack

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