CVE Vulnerabilities

CVE-2021-30852

Access of Resource Using Incompatible Type ('Type Confusion')

Published: Aug 24, 2021 | Modified: Nov 07, 2023
CVSS 3.x
8.8
HIGH
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

A type confusion issue was addressed with improved memory handling. This issue is fixed in iOS 14.8 and iPadOS 14.8, tvOS 15, watchOS 8, iOS 15 and iPadOS 15. Processing maliciously crafted web content may lead to arbitrary code execution.

Weakness

The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

Affected Software

Name Vendor Start Version End Version
Ipados Apple * 14.8 (excluding)
Iphone_os Apple * 14.8 (excluding)
Macos Apple * 12.0.1 (excluding)
Tvos Apple * 15.0 (excluding)
Watchos Apple * 8.0 (excluding)

Extended Description

When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties. In languages without memory safety, such as C and C++, type confusion can lead to out-of-bounds memory access. While this weakness is frequently associated with unions when parsing data with many different embedded object types in C, it can be present in any application that can interpret the same variable or memory location in multiple ways. This weakness is not unique to C and C++. For example, errors in PHP applications can be triggered by providing array parameters when scalars are expected, or vice versa. Languages such as Perl, which perform automatic conversion of a variable of one type when it is accessed as if it were another type, can also contain these issues.

References