CVE-2018-8373
Microsoft Scripting Engine Memory Corruption Vulnerability
Microsoft Internet Explorer Scripting Engine
A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka "Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10. This CVE ID is unique from CVE-2018-8353, CVE-2018-8355, CVE-2018-8359, CVE-2018-8371, CVE-2018-8372, CVE-2018-8385, CVE-2018-8389, CVE-2018-8390.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 25 March 2022. US federal agencies were required to remediate it by 15 April 2022.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 61.5%, which is higher than 99.2% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2018-8373 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2018-8373.
What does CVE-2018-8373 affect?
CVE-2018-8373 affects Microsoft Internet Explorer Scripting Engine. A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka "Scripting Engine Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10. This CVE ID is unique from CVE-2018-8353, CVE-2018-8355, CVE-2018-8359, CVE-2018-8371, CVE-2018-8372, CVE-2018-8385, CVE-2018-8389, CVE-2018-8390.
How severe is CVE-2018-8373?
CVE-2018-8373 is rated HIGH with a CVSS base score of 7.5. EPSS puts the probability of exploitation in the next 30 days at 61.5%, higher than 99.2% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 15 April 2022.
How should organisations respond to CVE-2018-8373?
Apply the vendor patch for Microsoft Internet Explorer Scripting Engine as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.