AndroidOperating system · Google

CVE-2020-27035

MEDIUM · 5.5 CVSS v3.1 Published 2020-12-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
57/100
Remediation priority · Elevated
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 priorLinearAllocation of C2AllocatorIon.cpp, there is a possible use-after-free due to improper locking. This could lead to local information disclosure in the media codec with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-152239213

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 priorLinearAllocation function of C2AllocatorIon.cpp in Android's media codec subsystem. The root cause is improper locking, where synchronization mechanisms fail to properly protect memory allocation/deallocation, allowing memory to be accessed after being freed. This enables local information disclosure.

MitigationApply the Android security patch for Android-11 that addresses this vulnerability. Organizations should ensure devices receive the October 2020 Android security update or later.

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:= 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
None
Availability
None

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

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. Check Android version
    Run 'adb shell getprop ro.build.version.release' or check Settings > About Phone > Android version
    Affected if Version is exactly 11.0 (Android 11)
  2. Verify C2 Codec component is present
    Check for the presence of the media.codec service by running 'adb shell dumpsys media.codec'
    Affected if The C2AllocatorIon component is loaded and active in the media codec service
  3. Confirm Codec 2 (C2) allocator is in use
    Run 'adb shell dumpsys media.codec | grep -i allocator' to see which allocators are instantiated
    Affected if C2AllocatorIon is listed as an active allocator in the codec output
  4. Check if affected media service is running
    Run 'adb shell ps -A | grep media' to verify the media.codec service process is running
    Affected if The media.codec service process is running on the device

A device is affected if it is running Android 11.0 and uses the C2AllocatorIon component in its media codec subsystem, as indicated by the media.codec service running and showing C2 allocator in its dump output.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Android security patch for Android-11 that addresses this vulnerability. Organizations should ensure devices receive the October 2020 Android security update or later.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,580
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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-2020-27035 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