AndroidOperating system · Google

CVE-2021-0611

HIGH · 7.8 CVSS v3.1 Published 2021-09-27
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In m4u, there is a possible memory corruption due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05403499; Issue ID: ALPS05425810.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A use-after-free vulnerability exists in the m4u (Memory Management Unit) component where memory is accessed after being freed, causing memory corruption. This allows a local attacker with System execution privileges to escalate privileges to root. No user interaction is required for exploitation.

MitigationApply patch ALPS05403499 to address the use-after-free in the m4u component. This is a vendor-supplied fix that should be integrated into the affected Android/system image.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
AndroidOperating system
Affected:= 10.0= 11.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Android version
    Run 'getprop ro.build.version.release' or check Settings > About Phone > Android version
    Affected if The version is exactly 10.0 or 11.0 (these are the only affected versions listed)
  2. Identify m4u component presence
    Check for m4u kernel module or device node - look in /sys/module/ for 'm4u' or check /dev/ for m4u-related device files
    Affected if The m4u component is present and loaded on the device
  3. Check for patch ALPS05403499
    Run 'getprop' to check build properties or inspect vendor/kernel patches - grep for 'ALPS05403499' in system or vendor partitions if accessible
    Affected if The patch ALPS05403499 is NOT applied (vulnerable) or cannot be verified as applied

The device is affected if it runs Android 10.0 or 11.0, contains the m4u component, and lacks the ALPS05403499 patch. The attacker must already have System-level execution privileges to exploit this use-after-free vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply patch ALPS05403499 to address the use-after-free in the m4u component. This is a vendor-supplied fix that should be integrated into the affected Android/system image.

Recommended fix Moderate confidence
  1. 1. Obtain the Mediatek patch ALPS05403499 which addresses the use-after-free vulnerability in the m4u driver (Issue ID ALPS05425810)
  2. 2. Contact Mediatek directly through your device OEM or Mediatek's corporate channels to receive the patched m4u driver binary/module
  3. 3. Apply the patch through your Android device's vendor-specific update mechanism, as this is a Mediatek GPU/memory management driver issue not covered by standard AOSP patches
  4. 4. Ensure the device receives the corresponding Android Security Patch Level that includes this fix; check the Android Security Bulletin for the month the fix was released
  5. 5. After patching, verify the m4u driver version includes the fix by checking /vendor or /system/vendor driver versions
Caveat This is a vendor-specific Mediatek driver patch; there are no standard upgrade paths - the fix comes through Mediatek's proprietary driver updates distributed via OEM device updates

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing8.0 h
  • Review / QA4.0 h
18.0 hours of engineering $3,040
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-0611 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data