dbcve.org
AndroidOperating system · Google

CVE-2018-21081

CRITICAL · 9.1 CVSS v3.1 Published 2020-04-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
An issue was discovered on Samsung mobile devices with N(7.x) software. In Dual Messenger, the second app can use the runtime permissions of the first app without a user's consent. The Samsung ID is SVE-2017-11018 (March 2018).

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

On Samsung mobile devices running Android N (7.x), the Dual Messenger feature contains a vulnerability where the second (cloned) instance of an app can inherit and use the runtime permissions already granted to the original first app without obtaining separate user consent. This allows the cloned app to access sensitive capabilities (camera, microphone, contacts, storage) that the user only intended to grant to the primary app.

MitigationSamsung released a firmware patch (SVE-2017-11018) addressing this issue. Organizations should ensure affected devices are updated to the patched Samsung software version. As a control, consider disabling Dual Messenger via MDM until devices are patched.

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:= 7.0= 7.1.0= 7.1.1= 7.1.2

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify device and Android version
    Check if the device is a Samsung model and verify the Android version is 7.0, 7.1.0, 7.1.1, or 7.1.2 via Settings > About Phone > Software Information
    Affected if Device is a Samsung running Android 7.0-7.1.2 (exact versions listed)
  2. Confirm Dual Messenger feature is enabled
    Navigate to Settings > Advanced Features > Dual Messenger on the Samsung device and check if the feature toggle is turned on
    Affected if Dual Messenger is enabled on an affected Android version
  3. Identify cloned app instances
    In the Dual Messenger settings screen, review the list of apps that have a second (cloned) instance created
    Affected if Any apps appear in the Dual Messenger list as cloned instances
  4. Verify permission inheritance behavior
    Check if the cloned app can access sensitive capabilities (camera, microphone, contacts, storage) without prompting for separate permission grants that the original app already has
    Affected if Cloned apps inherit permissions from original apps without additional user consent prompts

A Samsung device on Android 7.0-7.1.2 with Dual Messenger enabled and at least one cloned app instance is affected by this permission inheritance vulnerability.

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

Samsung released a firmware patch (SVE-2017-11018) addressing this issue. Organizations should ensure affected devices are updated to the patched Samsung software version. As a control, consider disabling Dual Messenger via MDM until devices are patched.

Recommended fix Moderate confidence

Any Samsung security patch released after March 2018, or Android 8.0 (Oreo) and later

  1. Check for and install the latest Samsung security patch (released after March 2018) via Settings > Software Update > Download and install
  2. If available, upgrade the device to Android 8.0 (Oreo) or higher which contains the fix
  3. As a workaround, disable Dual Messenger feature via Settings > Advanced features > Dual Messenger
  4. Verify the fix is applied by checking Settings > Software Update to confirm the device has March 2018 or later security patches
Caveat Upgrading to Android 8.0+ may remove Dual Messenger functionality entirely; verify app compatibility before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2018-21081 in production — separate from our analysis above.

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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