CVE-2021-39782

Local privilege escalation via unchecked SIM-file modification

Published Mar 30, 2022 · Updated Aug 4, 2024

Privilege escalation in Android 12L Telephony allows local users to modify the PLMN SIM file without user interaction. The Telephony component omits a permission check before permitting a write to the PLMN SIM file, allowing an unauthorized caller to alter it. A local low-privileged context is required, and successful exploitation raises privileges without additional execution privileges.

CVSS severity7.8
High
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

Privilege escalation in Android 12L Telephony allows local users to modify the PLMN SIM file without user interaction. The Telephony component omits a permission check before permitting a write to the PLMN SIM file, allowing an unauthorized caller to alter it. A local low-privileged context is required, and successful exploitation raises privileges without additional execution privileges.

The record

CVE
CVE-2021-39782
Published
Mar 30, 2022
Updated
Aug 4, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-269, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 30, 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

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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-12L

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-12L

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P

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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1068Exploitation for Privilege Escalation

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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