CVE-2021-0309
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 onCreate of grantCredentialsPermissionActivity, there is a confused deputy. This could lead to local information disclosure and account access with no additional execution privileges needed. User interaction is needed for exploitation. Product: Android; Versions: Android-8.1, Android-9, Android-10, Android-11, Android-8.0; Android ID: A-158480899.
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 confidenceA confused deputy vulnerability exists in the onCreate method of grantCredentialsPermissionActivity in Android. The activity that handles granting credentials/permissions access to apps fails to properly validate the requester, potentially allowing a malicious local app to trick users into granting credential access permissions they would not otherwise approve, leading to local information disclosure and unauthorized account access.
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= 8.0= 8.1= 9.0= 10.0= 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
- 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 checksWork through these to decide whether this CVE applies to you.
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Check Android OS versionGo to Settings > About Phone > Android version (or Software version). Record the exact version number shown.Affected if The device runs Android 8.0, 8.1, 9.0, 10.0, or 11.0 (any of the listed affected versions).
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Check security patch levelGo to Settings > About Phone > Security patch level (or Kernel version > Android security patch level). Record the date shown.Affected if The security patch level is earlier than January 2021, meaning the CVE-2021-0309 fix has not been applied.
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Verify the vulnerable component existsCheck if the Settings app and credential permission dialogs function normally on the device. A device with the vulnerable code would allow the grantCredentialsPermissionActivity to process requests without proper requester validation.Affected if The device is on an affected Android version (8.0-11.0) and has not received the January 2021 security patch.
The device is affected if it runs Android 8.0 through 11.0 and has a security patch level earlier than January 2021, as this indicates the fix for the grantCredentialsPermissionActivity confused deputy flaw has not been applied.
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 dataApply the Android security patch level that addresses CVE-2021-0309. Users should ensure their devices receive regular security updates from their device manufacturer or Google. Organizations should inventory affected Android devices and prioritize patching.
- Consultation4.0 h
- Implementation2.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,160.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0309 — 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-2021-0309 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
- No spam, self-promotion, credentials, or personal data