CVE-2021-39760
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 AudioService, there is a possible way to determine whether an app is installed, without query permissions, due to side channel information disclosure. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12LAndroid ID: A-194110526
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 · moderate confidenceCVE-2021-39760 is a side-channel information disclosure vulnerability in Android's AudioService (Android-12L). The flaw allows a local attacker to determine whether a specific application is installed on the device without requiring the usual QUERY_ALL_PACKAGES or PACKAGE_QUERY permissions. This is accomplished through side-channel analysis of AudioService behavior, enabling reconnaissance of installed apps with no user interaction and no additional execution privileges needed.
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= 12.1CVSS 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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Identify Android versionGo to Settings > About Phone > Android version or run 'getprop ro.build.version.release' via ADBAffected if Version displays 12.1 or 12L (Android 12.1) - this is the affected release
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Check security patch levelGo to Settings > About Phone > Security patch level or run 'getprop ro.build.version.security_patch' via ADBAffected if Patch level is earlier than January 2022 (2022-01-01) - unpatched devices are vulnerable
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Verify AudioService module presenceCheck if AudioService is active by examining running services: run 'dumpsys audio' via ADB shellAffected if AudioService responds to queries - the side-channel exists regardless of configuration, but only matters on affected Android versions
A device is affected if it runs Android 12.1 (12L) and has a security patch level earlier than the January 2022 update.
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.
dbcve · scopedThis is a platform-level vulnerability requiring a security patch from Google. Organizations should ensure Android devices receive the latest security updates (particularly the Android-12L January 2022 or subsequent security patches). There is no application-level mitigation; end-users must apply vendor-supplied system updates.
Android-12L with December 2021 security patch level or later
- Apply the December 2021 Android Security Update or later to your Android device
- Verify the security patch level includes the fix for CVE-2021-39760 in the Android Security Bulletin
- The fix was released as part of the Android-12L security update bundle
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,816.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39760 — 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-2021-39760 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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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.
- 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