Fortinet Discovers Microsoft Windows Network Connectivity Assistant Elevation of Privilege Vulnerability
Summary
Fortinet's FortiGuard Labs has discovered an elevation of privilege vulnerability in Microsoft Network Connectivity Assistant that allows adversaries to execute arbitrary code under system context.
The Network Connectivity Assistant (NCA) service provides DirectAccess connectivity status information as well as diagnostic support on the client. The NCA validates that DirectAccess is working end-to-end by attempting to reach internal resources defined by the administrator during the configuration of DirectAccess.
The vulnerability in the NCA service allows arbitrary program execution under system context. To exploit the vulnerability, an attacker would first have to log on to the system. Then the attacker could run a specially crafted application that could exploit the vulnerability and take control of the affected system.
Solutions
FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:MS.RPC.NcaSvc.Privilege.Escalation
Released Sep 04, 2019
Users should apply the solution provided by Microsoft.
Timeline
Fortinet reported the vulnerability to Microsoft on July 01, 2019.
Microsoft confirmed the vulnerability on July 22, 2019.
Microsoft released patch for the vulnerability on September 10, 2019.