CVE Vulnerabilities

CVE-2021-39841

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

Published: Sep 29, 2021 | Modified: Nov 07, 2023
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
6.8 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a Type Confusion vulnerability. An attacker could leverage this vulnerability to execute arbitrary code in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

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
Acrobat Adobe 20.001.30005 (including) 20.004.30006 (including)
Acrobat_reader Adobe 20.001.30005 (including) 20.004.30006 (including)

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