title: Low privilege user is able to exploit the service and gain SYSTEM privileges in UltraVNC server
description: UltraVNC is a free and open source remote pc access software. A vulnerability has been found in versions prior to 1.3.8.0 in which the DSM plugin module, which allows a local authenticated user to achieve local privilege escalation (LPE) on a vulnerable system. The vulnerability has been fixed to allow loading of plugins from the installed directory. Affected users should upgrade their UltraVNC to 1.3.8.1. Users unable to upgrade should not install and run UltraVNC server as a service. It is advisable to create a scheduled task on a low privilege account to launch WinVNC.exe instead. There are no known workarounds if winvnc needs to be started as a service.
problem types: CWE-269: Improper Privilege Management
affected:
{
vendor: ultravnc
product: UltraVNC
versions:
version: < 1.3.8.0, status: affected
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
attackVector: LOCAL
attackComplexity: LOW
privilegesRequired: LOW
userInteraction: NONE
scope: CHANGED
confidentialityImpact: HIGH
integrityImpact: HIGH
availabilityImpact: HIGH
baseScore: 8.8
baseSeverity: HIGH
]