CVE Vulnerabilities

CVE-2021-24044

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

Published: Jan 15, 2022 | Modified: Jan 24, 2022
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
7.5 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:P
RedHat/V2
RedHat/V3
Ubuntu

By passing invalid javascript code where await and yield were called upon non-async and non-generator getter/setter functions, Hermes would invoke generator functions and error out on invalid await/yield positions. This could result in segmentation fault as a consequence of type confusion error, with a low chance of RCE. This issue affects Hermes versions prior to v0.10.0.

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
Hermes Facebook * 0.10.0 (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