CVE-2023-21186
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 LogResponse of Dns.cpp, there is a possible out of bounds read due to a missing bounds check. This could lead to remote denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-13Android ID: A-261079188
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 confidenceA missing bounds check in the LogResponse function of Dns.cpp allows an out-of-bounds read when processing DNS responses. This can cause a denial of service condition without requiring any special privileges or user interaction, as the vulnerability exists in the DNS response parsing code path.
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= 13.0CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 versionGo to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADBAffected if Version is exactly 13.0 (the only affected version listed)
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Verify DNS response processing is activeConfirm the device has network connectivity and is capable of resolving DNS queries. Check if the DNS service is running via 'ps -A | grep dns' or similar process listingAffected if DNS resolution is enabled and the device processes network requests
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Identify if DNS logging/debug feature is enabledInspect system logs or debug settings related to DNS. On Android, this may be controlled by developer options or logging settings. Check logcat for DNS-related debug outputAffected if DNS response logging or debug features are turned on, which would trigger the LogResponse function in Dns.cpp
A user is affected if their Android device runs version 13.0 and processes DNS responses with the logging feature enabled, exposing them to the out-of-bounds read in the LogResponse function.
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.
dbcve · scopedApply the Android security patch (Android-13) that addresses CVE-2023-21186. Users should ensure their devices receive the latest system updates containing the fix for this vulnerability.
Android 13 with February 2024 security patch level or later
- 1. Go to Settings on the Android device
- 2. Navigate to System > System update (or Software update)
- 3. Check for available updates
- 4. If an update is available, download and install it
- 5. Ensure the device updates to a security patch level of February 2024 or later to receive the fix for this vulnerability
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation4.0 h
- Testing8.0 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 $5,504.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-21186 — 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-2023-21186 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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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.
- 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