CVE-2021-38646
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Microsoft Office
Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 28 March 2022. US federal agencies were required to remediate it by 18 April 2022. CISA records this vulnerability as known to be used in ransomware campaigns.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 8%, which is higher than 94.6% 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:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2021-38646 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2021-38646.
What does CVE-2021-38646 affect?
CVE-2021-38646 affects Microsoft Office. Microsoft Office Access Connectivity Engine Remote Code Execution Vulnerability
How severe is CVE-2021-38646?
CVE-2021-38646 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 8%, higher than 94.6% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 18 April 2022.
How should organisations respond to CVE-2021-38646?
Apply the vendor patch for Microsoft Office 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.