AndroidOperating system · Google

CVE-2016-0818

MEDIUM · 5.9 CVSS v3.0 Published 2016-03-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
68/100
Remediation priority · Elevated
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
The caching functionality in the TrustManagerImpl class in TrustManagerImpl.java in Conscrypt in Android 4.x before 4.4.4, 5.x before 5.1.1 LMY49H, and 6.x before 2016-03-01 mishandles the distinction between an intermediate CA and a trusted root CA, which allows man-in-the-middle attackers to spoof servers by leveraging access to an intermediate CA to issue a certificate, aka internal bug 26232830.

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

The TrustManagerImpl class in Conscrypt (Android's SSL/TLS provider) contains a caching flaw where intermediate CA certificates are incorrectly treated as trusted root CAs. This allows an attacker with access to a valid intermediate CA certificate to issue fraudulent server certificates and perform man-in-the-middle attacks, bypassing proper certificate chain validation.

MitigationUpdate Android devices to version 4.4.4, 5.1.1 LMY49H, or the March 2016 6.x security patch level to receive the corrected TrustManager certificate chain validation logic.

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:= 4.0= 4.0.1= 4.0.2= 4.0.3= 4.0.4= 4.1= 4.1.2= 4.2= 4.2.1= 4.2.2= 4.3= 4.3.1

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

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/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 Android version
    Go to Settings > About Phone (or About Device) > Android version, or run 'getprop ro.build.version.release' via ADB shell
    Affected if Version is 4.0, 4.0.1, 4.0.2, 4.0.3, 4.0.4, 4.1, 4.1.2, 4.2, 4.2.1, 4.2.2, 4.3, or 4.3.1
  2. Check Conscrypt TrustManager implementation
    Examine the Conscrypt library in /system/lib/ or within the Android framework JAR at /system/framework/conscrypt.jar for the TrustManagerImpl class
    Affected if TrustManagerImpl class is present and processes SSL/TLS connections on the device
  3. Review any apps or system services that use HTTPS, VPN connections, or other TLS-protected communication
    Affected if Any app or service uses SSL/TLS networking without additional certificate pinning protection

The device is affected if it runs Android version 4.0 through 4.3.1 and uses Conscrypt TrustManager for certificate chain validation, allowing intermediate CA certificates to be incorrectly trusted for MITM attacks.

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

Update Android devices to version 4.4.4, 5.1.1 LMY49H, or the March 2016 6.x security patch level to receive the corrected TrustManager certificate chain validation logic.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
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Scan for this in your stack

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dbcve dependency scanner

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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-2016-0818 in production — separate from our analysis above.

No notes yet

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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
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