CVE-2023-21313
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 Core, there is a possible way to forward calls without user knowledge due to a missing permission check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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 Android Core, a missing permission check in the call forwarding functionality allows an application to forward calls without user knowledge or authorization. This constitutes a local privilege escalation as an app can modify call routing without holding the required MODIFY_PHONE_STATE permission.
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< 14.0CVSS 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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Check Android versionGo to Settings > About Phone > Android version or run 'getprop ro.build.version.release' via ADB shellAffected if Version is below 14.0 (Android 14)
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Verify MODIFY_PHONE_STATE permission statusCheck if your device or any installed app holds the MODIFY_PHONE_STATE permission using 'dumpsys package <package_name>' for system phone apps via ADBAffected if Apps without this permission can modify call forwarding settings
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Inspect TelecomManager call forwarding accessUse 'dumpsys telecom' via ADB shell to examine the TelecomManager service configuration and check if call forwarding operations are restrictedAffected if Call forwarding modifications are allowed without permission verification
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Review installed apps for dangerous permissionsRun 'pm list permissions -d' via ADB to list apps with dangerous permissions, then cross-reference with phone/CallForwarding functionalityAffected if Apps without MODIFY_PHONE_STATE can modify call routing
Your environment is affected if running Android version less than 14.0 AND apps can modify call forwarding settings without holding the MODIFY_PHONE_STATE permission.
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 · scoped14.0
Add appropriate permission checks (e.g., MODIFY_PHONE_STATE or equivalent) before allowing any call forwarding operations in the Android phone service. Apply the principle of least privilege to ensure only authorized system components can modify call routing.
Android 14.0
- Upgrade the device to Android 14.0 or later to receive the security patch that addresses the missing permission check in Core for call forwarding.
- Verify the Android version by navigating to Settings > About Phone > Android version to confirm the upgrade was successful.
- Ensure monthly security patches are applied after upgrading to maintain ongoing protection against similar vulnerabilities.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-21313 — 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-2023-21313 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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