The type inference system in Firefox before 66.0 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). This allows for possible arbitrary reading and writing of objects during an exploitable crash.
The type inference system in Firefox before 66.0 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). This allows for possible arbitrary reading and writing of objects during an exploitable crash.
https://www.mozilla.org/en-US/security/advisories/mfsa2019-07/#CVE-2019-9791 https://bugzilla.mozilla.org/show_bug.cgi?id=1530958