CVE-2021-0705

Local privilege escalation via retained notification token

Published Oct 22, 2021 · Updated Aug 3, 2024

Elevation of privilege in Android 10 and 11 allows local users to retain foreground-service permissions through a crafted notification. NotificationManagerService.sanitizeSbn returns an app's active notification with an allowlist token intact, letting the app fire its PendingIntent to bypass background activity and foreground-service restrictions. A locally installed malicious app needs no additional execution privileges or user interaction and can keep its service and granted permissions active.

CVSS severity7.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Elevation of privilege in Android 10 and 11 allows local users to retain foreground-service permissions through a crafted notification. NotificationManagerService.sanitizeSbn returns an app's active notification with an allowlist token intact, letting the app fire its PendingIntent to bypass background activity and foreground-service restrictions. A locally installed malicious app needs no additional execution privileges or user interaction and can keep its service and granted permissions active.

The record

CVE
CVE-2021-0705
Published
Oct 22, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
T1541
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Oct 22, 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-10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Androidversion=Android-11 Android-10

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV: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

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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

T1541Foreground Persistence

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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