Apple iOS/iPadOS up to 15.1.1 WebKit integer overflow

Summaryinfo

A vulnerability described as critical has been identified in Apple iOS and iPadOS up to 15.1.1. This affects an unknown function of the component WebKit. The manipulation results in integer overflow. This vulnerability is reported as CVE-2021-30952. The attack can be launched remotely. Moreover, an exploit is present. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Apple iOS and iPadOS up to 15.1.1 (Smartphone Operating System). It has been classified as critical. Affected is an unknown code block of the component WebKit. The manipulation with an unknown input leads to a integer overflow vulnerability. CWE is classifying the issue as CWE-190. The product performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

An integer overflow was addressed with improved input validation. This issue is fixed in tvOS 15.2, macOS Monterey 12.1, Safari 15.2, iOS 15.2 and iPadOS 15.2, watchOS 8.3. Processing maliciously crafted web content may lead to arbitrary code execution.

The weakness was disclosed 12/13/2021 by WeBin as HT212976 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability is traded as CVE-2021-30952. Successful exploitation requires user interaction by the victim. Technical details are unknown but an exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 03/07/2026). It is expected to see the exploit prices for this product increasing in the near future. The advisory points out:

Processing maliciously crafted web content may lead to arbitrary code execution

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 241427 (RHEL 7 : webkitgtk4 (RHSA-2025:10364)), which helps to determine the existence of the flaw in a target environment. This issue was added on 03/05/2026 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 03/26/2026:

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Upgrading to version 15.2 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

An integer overflow was addressed with improved input validation.

The vulnerability is also documented in the databases at Tenable (241427) and CERT Bund (WID-SEC-2026-0631). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Apple macOS

Productinfo

Type

• Smartphone Operating System

Vendor

• Apple

Name

• iOS
• iPadOS

Version

• 15.1.0
• 15.1.1

License

• commercial

Website

• Vendor: https://www.apple.com/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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