CVE-2016-2420
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 · uneditedrootdir/init.rc in Android 4.x before 4.4.4 does not ensure that the /data/tombstones directory exists for the Debuggerd component, which allows attackers to gain privileges via a crafted application, aka internal bug 26403620.
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 confidenceThis is a local privilege escalation vulnerability in Android 4.x where the init.rc startup script fails to create the /data/tombstones directory before the Debuggerd component attempts to use it. An attacker can exploit this by crafting an application that creates the directory with permissive ownership/permissions before the system does, allowing privilege escalation.
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= 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= 4.3.1CVSS 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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Check Android versionRun 'getprop ro.build.version.release' or check Settings > About Phone > Android versionAffected if The 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
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Inspect /data/tombstones directory permissionsRun 'ls -la /data/tombstones' with root access to see ownership and permission bitsAffected if The directory exists with permissive ownership (not owned by system:system) or overly open permissions (e.g., world-writable)
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Verify init.rc directory creationCheck the init.rc file (typically in / or /system/core/rootdir/) for a 'mkdir /data/tombstones' command appearing before the Debuggerd service definitionAffected if No 'mkdir /data/tombstones' command exists in init.rc, or it appears after the Debuggerd service entry
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Check Debuggerd configurationRun 'grep -A5 debuggerd /init.rc' to locate the Debuggerd service entry and confirm it starts after any directory creationAffected if Debuggerd service starts before /data/tombstones is created, or the mkdir command is missing entirely
You are affected if your Android version is 4.0 through 4.3.1 and the /data/tombstones directory is either missing, created with permissive ownership, or not properly initialized in init.rc before Debuggerd starts.
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 for CVE-2016-2420 (April 2016 or later), which adds proper directory creation for /data/tombstones in init.rc before Debuggerd starts. For custom ROMs, add 'mkdir /data/tombstones 0775 system system' to init.rc before the Debuggerd service definition.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-2420 — 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-2016-2420 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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- Version or environment caveats, and links to real fixes
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