Apple iOS up to 12.5.2 WebKit Storage use after free

Summaryinfo

A vulnerability, which was classified as critical, was found in Apple iOS up to 12.5.2. This affects an unknown function of the component WebKit Storage. Such manipulation leads to use after free. This vulnerability is uniquely identified as CVE-2021-30661. The attack can be launched remotely. Moreover, an exploit is present. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Apple iOS up to 12.5.2 (Smartphone Operating System). Affected by this issue is some unknown functionality of the component WebKit Storage. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A use after free issue was addressed with improved memory management. This issue is fixed in Safari 14.1, iOS 12.5.3, iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5, macOS Big Sur 11.3. Processing maliciously crafted web content may lead to arbitrary code execution. Apple is aware of a report that this issue may have been actively exploited..

The weakness was disclosed 05/03/2021 by yangkang as HT212341 as confirmed advisory (Website). The advisory is shared for download at support.apple.com. This vulnerability is handled as CVE-2021-30661. Successful exploitation requires user interaction by the victim. Technical details are unknown but a private exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/29/2025). 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. Apple is aware of a report that this issue may have been actively exploited.

It is declared as attacked. The vulnerability scanner Nessus provides a plugin with the ID 223935 (Linux Distros Unpatched Vulnerability : CVE-2021-30661), which helps to determine the existence of the flaw in a target environment. This issue was added on 11/03/2021 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 11/17/2021:

Apply updates per vendor instructions.

Upgrading to version 12.5.3 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability. The advisory contains the following remark:

A use after free issue was addressed with improved memory management.

The vulnerability is also documented in the databases at Zero-Day.cz (624), Tenable (223935) and EUVD (EUVD-2021-17578). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Smartphone Operating System

Vendor

• Apple

Name

• iOS

Version

• 12.5.0
• 12.5.1
• 12.5.2

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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