CVE-2019-9791

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 66 Firefox ESR versions prior to 60.6 Thunderbird versions prior to 60.6

Description The issue is related to the IonMonkey just-in-time (JIT) compiler, which allows for type confusions between arbitrary objects when compiled and when the constructor function is entered through on-stack replacement (OSR). This can lead to possible arbitrary reading and writing of objects during an exploitable crash. The vulnerability is associated with a type conversion error when accessing arbitrary objects during compilation.

Recommendations For Firefox versions prior to 66, update to version 66 or later. For Firefox ESR versions prior to 60.6, update to version 60.6 or later. For Thunderbird versions prior to 60.6, update to version 60.6 or later.