CVE-2021-1796
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 · uneditedAn out-of-bounds write was addressed with improved input validation. This issue is fixed in iOS 14.4 and iPadOS 14.4. A remote attacker may be able to cause 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 confidenceA memory corruption vulnerability in iOS/iPadOS where improper input validation allows an out-of-bounds write operation, enabling a remote attacker to achieve arbitrary code execution without user interaction beyond being on a malicious network or visiting a crafted webpage.
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< 14.4< 14.4CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/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 checksWork through these to decide whether this CVE applies to you.
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Check iOS version on deviceGo to Settings > General > About on the iPhone or iPad and look at the 'Version' fieldAffected if Version displayed is less than 14.4 (e.g., 14.3, 14.2, 14.1, 13.x, etc.)
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Confirm iOS or iPadOSVerify whether the device runs iOS (iPhone) or iPadOS (iPad) from the same About screen under 'Model Name' or 'Model'Affected if Device runs any version below 14.4 on either iOS or iPadOS
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Check if device is still vulnerableCompare the full version number (including build number if visible) against 14.4Affected if The installed version number is lower than 14.4, regardless of build number
The device is affected if it runs iOS or iPadOS version 14.3 or any earlier version, as the vulnerability exists in all versions prior to 14.4.
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 · scoped14.4
Update affected iOS devices to version 14.4 or later (or current supported version) to apply the vendor patch that adds proper input validation bounds checking.
iOS 14.4 and iPadOS 14.4
- Check the current iOS/iPadOS version by going to Settings > General > About
- If version is less than 14.4, back up your device using iTunes or iCloud
- Connect device to power and WiFi
- Go to Settings > General > Software Update
- Download and install iOS 14.4 or iPadOS 14.4
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 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 $3,392.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1796 — 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-2021-1796 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