CVE-2020-0306
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 LLVM, there is a possible ineffective stack cookie placement due to stack frame double reservation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-139666480
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 confidenceIn LLVM, stack cookie placement becomes ineffective due to stack frame double reservation. This compiler-level flaw undermines a key security mitigation (stack canaries) that typically detects buffer overflows, potentially allowing attackers to bypass this protection mechanism and achieve local privilege escalation on affected Android-11 systems.
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= 11.0CVSS 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
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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 checksWork through these to decide whether this CVE applies to you.
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Verify Android version is 11.0Check system settings: Settings > About Phone > Android version, or run 'getprop ro.build.version.release' in adb shellAffected if Version shows 11.0 exactly (Android 11.0)
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Identify if binaries were compiled with vulnerable LLVM toolchainFor custom ROMs or system binaries: examine the compiler toolchain documentation or build logs to confirm LLVM was used; check if the LLVM version predates the fixAffected if System binaries or custom builds were compiled with an unpatched LLVM version that has the stack frame double reservation flaw
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Check for presence of security patch levelRun 'getprop ro.build.version.security_patch' in adb shell to retrieve the security patch date applied to the deviceAffected if Security patch level is earlier than the October 2020 Android security update that addresses CVE-2020-0306
A system is affected if it runs Android 11.0 and has not received the corresponding security patch that fixes the LLVM stack cookie placement vulnerability.
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 official Android security patch for CVE-2020-0306 (part of the Android-11 system update) to address the LLVM stack cookie placement vulnerability. Until patched, monitor for indicators of compiler-level exploitation.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-0306 — 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-2020-0306 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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- 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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