dbcve.org
AndroidOperating system · Google

CVE-2021-0576

HIGH · 7.8 CVSS v3.1 Published 2021-08-17
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 flv extractor, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android SoCAndroid ID: A-187236084

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

An out-of-bounds write vulnerability exists in Android's FLV media file extractor due to a missing bounds check during media parsing. This memory corruption flaw allows local privilege escalation without requiring additional execution privileges, and no user interaction is needed for exploitation.

MitigationApply the relevant Android security patch (part of the monthly Android Security Bulletin) to the affected Android SoC/framework implementation. For embedded systems, coordinate with the SoC vendor for firmware updates containing the patched media extractor.

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:all versions

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. Identify Android version and security patch level
    Go to Settings > About Phone > Android version and Build number to see the installed Android version and the security patch level (e.g., '2021-05-01' or later)
    Affected if The device is running any Android version without the May 2021 or later security patch level, and the device processes FLV media files through the built-in media extractor.
  2. Verify FLV media extraction capability
    Check if the Android device has a media extractor module capable of parsing FLV files. This is typically part of the MediaCodec and MediaExtractor framework in Android's media layer.
    Affected if The device has a media extractor that can process FLV files. The vulnerability exists in the FLV-specific parsing code within the extractor.
  3. Check for vulnerable media extractor library
    Inspect the system library files related to media extraction. On Android, the relevant library is typically libmediaextractor.so or similar framework libraries in /system/lib/ or /system/vendor/lib/. Look for the extractor component that handles FLV container format parsing.
    Affected if The FLV extractor library exists on the device and is being used by applications to parse FLV media files.
  4. Determine if third-party media players or apps use built-in FLV parsing
    Review installed applications that handle media files, particularly those that may automatically process FLV files using Android's native MediaExtractor API without additional codecs.
    Affected if Any application uses Android's built-in media framework to parse FLV files, which would invoke the vulnerable extractor code.

The device is affected if it runs any Android version prior to the May 2021 security patch and has the FLV media extractor component present and accessible to process FLV files.

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 the relevant Android security patch (part of the monthly Android Security Bulletin) to the affected Android SoC/framework implementation. For embedded systems, coordinate with the SoC vendor for firmware updates containing the patched media extractor.

Recommended fix High confidence

Android October 2021 Security Update (or later) - apply security patch level 2021-10-01 or higher

  1. Check your device's Android Security Patch Level in Settings > About Phone > Android Security Patch Level
  2. Ensure the device has the October 2021 Security Patch Level or later applied
  3. If available, upgrade your device to the latest Android version supported by your manufacturer
  4. For enterprise/IT-managed devices, apply the October 2021 Android security update through your device management system
Caveat None - this is a security-only patch that does not change functionality

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
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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Scan for this in your stack

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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-2021-0576 in production — separate from our analysis above.

No notes yet

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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