Description

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

References

https://www.mozilla.org/security/advisories/mfsa2019-11/

https://www.mozilla.org/security/advisories/mfsa2019-08/

https://www.mozilla.org/security/advisories/mfsa2019-07/

https://bugzilla.mozilla.org/show_bug.cgi?id=1532599

https://access.redhat.com/errata/RHSA-2019:0966

https://access.redhat.com/errata/RHSA-2019:1144

http://packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Value-Leak.html

Details

Risk Information

CVSS v2

CVSS v3