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DropboxApplication

CVE-2018-12271

MEDIUM · 6.4 CVSS v3.0 Published 2018-06-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
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 in the com.getdropbox.Dropbox app 100.2 for iOS. The LAContext class for Biometric (TouchID) validation allows authentication bypass by overriding the LAContext return Boolean value to be "true" because the kSecAccessControlUserPresence protection mechanism is not used. In other words, an attacker could authenticate with an arbitrary fingerprint. NOTE: the vendor indicates that this is not an attack of interest within the context of their threat model, which excludes iOS devices on which a jailbreak has occurred

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 confidence

The Dropbox iOS app (version 100.2) has an authentication bypass vulnerability in its TouchID/biometric validation. The LAContext class does not properly use the kSecAccessControlUserPresence protection mechanism, allowing an attacker to override the LAContext return value to 'true' and authenticate with an arbitrary fingerprint.

MitigationImplement proper kSecAccessControlUserPresence protection in the LAContext authentication flow to ensure TouchID validation cannot be bypassed or overridden.

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
DropboxApplication
Affected:= 100.2

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
Physical
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:P/AC:H/PR:N/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. Confirm Dropbox iOS app is installed
    Check installed applications on the iOS device
    Affected if The Dropbox iOS app is present on the device
  2. Identify installed Dropbox iOS version
    Navigate to iOS Settings > Apps > Dropbox or check the version in the App Store app listing
    Affected if The installed version is exactly 100.2
  3. Verify TouchID/biometric authentication is enabled
    Open Dropbox iOS app, go to Settings > Security, and check if TouchID login is turned on
    Affected if TouchID authentication is enabled in the app settings and version is 100.2

A user is affected if they have Dropbox iOS app version 100.2 installed with TouchID/biometric authentication enabled.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement proper kSecAccessControlUserPresence protection in the LAContext authentication flow to ensure TouchID validation cannot be bypassed or overridden.

Fix this in Dropbox Scoped from the published advisory
  • Consultation2.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,290
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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-2018-12271 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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