CVE-2016-0099
Microsoft Windows Secondary Logon Service Privilege Escalation Vulnerability
Microsoft Windows
The Secondary Logon Service in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 does not properly process request handles, which allows local users to gain privileges via a crafted application, aka "Secondary Logon Elevation of Privilege Vulnerability."
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 3 March 2022. US federal agencies were required to remediate it by 24 March 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 37%, which is higher than 98.5% 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:L/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2016-0099 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2016-0099.
What does CVE-2016-0099 affect?
CVE-2016-0099 affects Microsoft Windows. The Secondary Logon Service in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, and Windows 10 Gold and 1511 does not properly process request handles, which allows local users to gain privileges via a crafted application, aka "Secondary Logon Elevation of Privilege Vulnerability."
How severe is CVE-2016-0099?
CVE-2016-0099 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 37%, higher than 98.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 24 March 2022.
How should organisations respond to CVE-2016-0099?
Apply the vendor patch for Microsoft Windows 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.