dbcve.org
IpadosOperating system · Apple

CVE-2021-1748

HIGH · 8.8 CVSS v3.1 Published 2021-04-02
Fix available
A fix is available. Upgrade to 7.3 / 14.4 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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
A validation issue was addressed with improved input sanitization. This issue is fixed in tvOS 14.4, watchOS 7.3, iOS 14.4 and iPadOS 14.4. Processing a maliciously crafted URL may lead to arbitrary javascript 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 · high confidence

This is a validation vulnerability in iOS, iPadOS, watchOS, and tvOS where maliciously crafted URLs are not properly sanitized during processing, allowing arbitrary JavaScript code execution (XSS). The issue stems from inadequate input validation in URL handling routines.

MitigationUpdate affected devices to iOS/iPadOS 14.4, watchOS 7.3, or tvOS 14.4 or later to apply the patched input sanitization.

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
IpadosOperating system
Affected:< 14.4
Iphone OsOperating system
Affected:< 14.4
TvosOperating system
Affected:< 14.4
WatchosOperating system
Affected:< 7.3

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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 iOS or iPadOS version on Apple mobile devices
    On the device, open Settings > General > About and locate the 'Version' field. Note the numerical version displayed (e.g., 14.3, 14.4, 15.0).
    Affected if The version shown is less than 14.4 (for example, 14.3, 14.2, or earlier).
  2. Check watchOS version on Apple Watch
    Open the Watch app on the paired iPhone, go to General > About, and read the watchOS version. Alternatively, on Apple Watch go to Settings > General > About.
    Affected if The watchOS version is below 7.3 (such as 7.2, 7.1, or earlier).
  3. Check tvOS version on Apple TV
    On Apple TV, navigate to Settings > General > About and view the tvOS version number displayed.
    Affected if The tvOS version is less than 14.4 (for example, 14.3, 14.2, or older).
  4. Confirm the vulnerable URL handling component is in use
    This vulnerability affects URL processing across the operating system. Any application or service that handles external URLs could potentially trigger the flawed validation routine. No specific configuration flag exists to disable this component.
    Affected if The device runs an affected OS version AND processes external URLs through built-in system handlers (default behavior on all affected devices).

A device is affected if it runs iOS/iPadOS below 14.4, watchOS below 7.3, or tvOS below 14.4, as these versions contain the vulnerable URL validation code.

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 7.3 / 14.4 or later
Fixed in 7.314.4
Interim mitigation

Update affected devices to iOS/iPadOS 14.4, watchOS 7.3, or tvOS 14.4 or later to apply the patched input sanitization.

Recommended fix High confidence

iOS 14.4, iPadOS 14.4, tvOS 14.4, watchOS 7.3

  1. Identify the affected Apple device (iPhone, iPad, Apple TV, or Apple Watch)
  2. Go to Settings > General > Software Update on the device
  3. Download and install iOS 14.4 or iPadOS 14.4 for iPhone/iPad
  4. Download and install tvOS 14.4 for Apple TV
  5. Download and install watchOS 7.3 for Apple Watch via the Watch app on iPhone
  6. Ensure the device is connected to Wi-Fi and charging during the update process
  7. After updating, verify the update was successful by checking Settings > General > About for the version number

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

Fix this in Ipados 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

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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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-2021-1748 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