CVE-2021-24044: Access of Resource Using Incompatible Type in Hermes

Severity: Critical

CVSS Score: 9.8

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.