CVE-2021-0958

Local service hang via stalled Keymaster update

Published Dec 15, 2021 · Updated Aug 3, 2024

Denial of service in Android 11 and 12 Keystore compatibility code allows local users to hang cryptographic updates without interaction. KeyMintOperation::update assumes an older Keymaster backend always consumes input, so too little data in certain block modes leaves the compatibility loop making no progress. User-level code must reach the affected update path; the resulting infinite loop interrupts the calling cryptographic operation.

CVSS severityUnavailable
Unscored
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Android 11 and 12 Keystore compatibility code allows local users to hang cryptographic updates without interaction. KeyMintOperation::update assumes an older Keymaster backend always consumes input, so too little data in certain block modes leaves the compatibility loop making no progress. User-level code must reach the affected update path; the resulting infinite loop interrupts the calling cryptographic operation.

The record

CVE
CVE-2021-0958
Published
Dec 15, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 15, 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?

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  1. Affected versionversion=Android-11 Android-12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Androidversion=Android-11 Android-12

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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