SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-9815

If hyperthreading is not disabled, a timing attack vulnerability exists, similar to previous Spectre attacks.

HIGH 8.1EPSS 1.83%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.83%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

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.

CVSS 3.0
8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.83% probability · 78th percentile
CISA KEV
Not listed
Weakness
CWE-203
Affected
mozilla/firefox · mozilla/firefox esr · mozilla/thunderbird
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.