CVE-2019-9815

Published: 23 July 2019

If hyperthreading is not disabled, a timing attack vulnerability exists, similar to previous Spectre attacks. Apple has shipped macOS 10.14.5 with an option to disable hyperthreading in applications running untrusted code in a thread through a new sysctl. Firefox now makes use of it on the main thread and any worker threads. *Note: users need to update to macOS 10.14.5 in order to take advantage of this change.*. This vulnerability affects Thunderbird < 60.7, Firefox < 67, and Firefox ESR < 60.7.

Notes

mozjs contains a copy of the SpiderMonkey JavaScript engine

MacOS only fix, as it depends on a MacOS only feature

Status

Severity score breakdown

References

• https://www.mozilla.org/en-US/security/advisories/mfsa2019-13/#CVE-2019-9815
• https://www.mozilla.org/en-US/security/advisories/mfsa2019-15/#CVE-2019-9815
• https://www.cve.org/CVERecord?id=CVE-2019-9815
• NVD
• Launchpad
• Debian