CVE-2021-0445
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 · uneditedIn start of WelcomeActivity.java, there is a possible residual profile due to a confused deputy. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-9Android ID: A-172322502
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 confidenceThis is a local privilege escalation vulnerability in Android's WelcomeActivity.java component. The vulnerability stems from a confused deputy issue where a residual profile from a previous user session or context is not properly cleared during the activity's initialization, allowing a local attacker to exploit this lingering authorization state to escalate privileges without needing additional execution rights or user interaction.
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= 9.0= 11.0CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Check Android versionGo to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADB shellAffected if The displayed version is exactly 9.0 or exactly 11.0
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Verify WelcomeActivity component existsCheck system app roster for packages containing WelcomeActivity, or examine the system partition for the presence of WelcomeActivity.java in the compiled system appsAffected if WelcomeActivity component is present in the system image
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Confirm profile/session persistence capabilityInspect whether the device supports managed profiles or work profile functionality - check for 'android.app.ProfileOwner' or 'android.app.DeviceOwner' permissions in installed appsAffected if Profile or work profile features are enabled and residual session data could persist across activity restarts
A device is affected if it runs Android version 9.0 or 11.0 and contains the vulnerable WelcomeActivity component with profile persistence capabilities enabled.
Generated from the published advisory. Verify against your own configuration.
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 dataThe fix requires properly clearing all residual profile data and authorization contexts when WelcomeActivity starts, ensuring no privileged state persists between sessions or across different user contexts. Users should apply Android system updates that address this vulnerability.
- Consultation6.0 h
- Implementation12.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0445 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-0445 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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