Type confusion in Mozilla Firefox - CVE-2019-9791

Detailed vulnerability description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to a type confusion error within the type inference system. The system allows the compilation of functions that can cause type confusions between arbitrary objects when compiled through the IonMonkey just-in-time (JIT) compiler and when the constructor function is entered through on-stack replacement (OSR). A remote attacker can trick the victim to visit a specially crafted web page, trigger type confusion error and execute arbitrary code on the system with privileges of the current user.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.

How to mitigate CVE-2019-9791

Sources

• https://www.mozilla.org/en-US/security/advisories/mfsa2019-07/
• https://bugzilla.mozilla.org/show_bug.cgi?id=1530958