dbcve.org
AndroidOperating system · Google

CVE-2021-0573

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 asf 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-187231635

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 missing bounds check in Android's ASF (Advanced Systems Format) media extractor allows an out of bounds write, enabling local privilege escalation without additional execution privileges. The vulnerability stems from insufficient validation during ASF file parsing in the media framework.

MitigationApply the Android security patch that addresses CVE-2021-0573; for Android SoC implementations, ensure the media framework components are updated to include proper bounds checking in the ASF 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. Check Android security patch level
    Run 'getprop ro.build.version.security_patch' or check Settings > About Phone > Android security patch level. Compare the date to October 2021 (when CVE-2021-0573 was patched).
    Affected if The security patch level is earlier than October 2021, meaning the bounds check fix is not applied.
  2. Verify ASF extractor is present
    Check for the presence of media extractor libraries in /system/lib/ or /system/lib64/. Look for libmediaextractor.so or similar ASF-related components using 'find /system -name "*extractor*"'
    Affected if The ASF media extractor library exists and is loaded by the system.
  3. Confirm media framework handles ASF files
    Attempt to parse a test ASF file using the media framework API or check if apps can open ASF files. On command line, use 'mediainfo' or similar tool if available to verify ASF parsing capability.
    Affected if The system can process ASF files, indicating the vulnerable extractor code path is active.
  4. Check Android version
    Run 'getprop ro.build.version.release' to identify the Android version. Note that all versions are affected prior to the October 2021 patch.
    Affected if The device is running any Android version with a security patch level before the fix was applied.

A device is affected if it runs Android with a security patch level prior to October 2021 and has the ASF media extractor enabled, as the missing bounds check in ASF parsing allows the out-of-bounds write vulnerability to be exploitable.

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 Android security patch that addresses CVE-2021-0573; for Android SoC implementations, ensure the media framework components are updated to include proper bounds checking in the ASF extractor.

Recommended fix Moderate confidence

Android devices with September 2021 security patch level (2021-09-01) or later

  1. 1. Check the current Android security patch level on the affected device in Settings > Security > Security update
  2. 2. Apply the latest Android security update available for the device (typically a monthly security patch)
  3. 3. Verify the security patch level has been updated to September 2021 or later via Settings > About Phone > Security Patch Level
  4. 4. If the device manufacturer has not released an update containing the fix, consider upgrading to a device that receives regular security updates or a newer Android version that includes the fix
  5. 5. As a workaround, avoid processing untrusted ASF media files until the device is updated

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
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2021-0573 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