Iphone OsOperating system · Apple

CVE-2021-30800

HIGH · 8.8 CVSS v3.1 Published 2021-09-08
Fix available
A fix is available. Upgrade to 14.7 or later.
See remediation →
93/100
Remediation priority · Urgent
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
This issue was addressed with improved checks. This issue is fixed in iOS 14.7. Joining a malicious Wi-Fi network may result in a denial of service or arbitrary code execution.

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 confidence

A vulnerability in iOS Wi-Fi network handling allows a malicious Wi-Fi network to cause denial of service or potentially execute arbitrary code on affected devices. The issue was addressed with improved validation checks and is fixed in iOS 14.7 and later versions.

MitigationUpgrade affected iOS devices to version 14.7 or later to remediate this vulnerability.

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
Iphone OsOperating system
Affected:< 14.7

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check the iOS version installed on the iPhone
    Open Settings app, go to General, tap About, and read the number next to 'Version'
    Affected if The displayed version number is lower than 14.7 (for example, 14.6.1, 14.6, 14.5, etc.)
  2. Confirm the iOS build number (optional for certainty)
    In Settings > General > About, look at the 'Build Number' entry
    Affected if The build number corresponds to a version earlier than the iOS 14.7 release build (contact Apple support or check release notes for specific build numbers)
  3. Identify the device model to confirm it is an iPhone
    In Settings > General > About, check the model name or number under 'Model Name'
    Affected if The device is an iPhone running any iOS version below 14.7

The device is affected if it is an iPhone running iOS version 14.6 or earlier; devices on iOS 14.7 or later are not vulnerable.

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.

dbcve · scoped
Upgrade available Upgrade to 14.7 or later
Fixed in 14.7
Interim mitigation

Upgrade affected iOS devices to version 14.7 or later to remediate this vulnerability.

Recommended fix High confidence

iOS 14.7

  1. Back up your iPhone to iCloud or your computer before updating
  2. Connect your device to Wi-Fi and ensure the battery is sufficiently charged (at least 50%)
  3. Go to Settings > General > Software Update
  4. Tap 'Download and Install' to download iOS 14.7
  5. Follow the on-screen prompts to complete the installation
  6. After the device restarts, verify the update by checking Settings > General > About > Version (should show 14.7 or later)
Caveat iOS upgrades may have compatibility issues with older apps or accessories; review app updates after upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Iphone Os Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-30800 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-30800 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
  • No spam, self-promotion, credentials, or personal data