CVE-2021-0678

Local privilege escalation via unchecked buffer write

Published Dec 17, 2021 · Updated Aug 3, 2024

Out-of-bounds write in MediaTek APUSYS on Android 10.0, 11.0, and 12.0 allows local users with System privileges to gain elevated privileges. APUSYS fails to enforce a bounds check before writing to a memory buffer, allowing data to be written beyond the intended boundary. Exploitation requires local System execution privileges, needs no user interaction, and can raise the attacker's privileges.

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

Out-of-bounds write in MediaTek APUSYS on Android 10.0, 11.0, and 12.0 allows local users with System privileges to gain elevated privileges. APUSYS fails to enforce a bounds check before writing to a memory buffer, allowing data to be written beyond the intended boundary. Exploitation requires local System execution privileges, needs no user interaction, and can raise the attacker's privileges.

The record

CVE
CVE-2021-0678
Published
Dec 17, 2021
Updated
Aug 3, 2024
Vendor
MediaTek
Product
MediaTek APUSYS
Classifications
CWE-119, T1404
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 17, 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 10.0, 11.0, 12.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

MediaTek · MediaTek APUSYSversion=Android 10.0, 11.0, 12.0

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

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
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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