Any unauthenticated user can reset the WorkTime on-prem database configuration by sending a specific HTTP request to the WorkTime server. No authorization check is applied here.

The server API endpoint /report/internet/urls reflects received data into the HTML response without applying proper encoding or filtering. This allows an attacker to execute arbitrary JavaScript in the victim's browser if the victim opens a URL prepared by the attacker.

An attacker can exploit the update behavior of the WorkTime monitoring daemon to elevate privileges on the local system to NT Authority\SYSTEM. A malicious executable must be named  WTWatch.exe and dropped in the C:\ProgramData\wta\ClientExe directory, which is writable by "Everyone". The executable will then be run by the WorkTime monitoring daemon.

An authenticated attacker with minimal permissions can exploit a SQL injection in the WorkTime server "widget" API endpoint to inject SQL queries. If the Firebird backend is used, attackers are able to retrieve all data from the database backend. If the MSSQL backend is used the attacker can execute arbitrary SQL statements on the database backend and gain access to sensitive data.

An unauthenticated attacker can inject OS commands when calling a server API endpoint in NesterSoft WorkTime. The server API call to generate and download the WorkTime client from the WorkTime server is vulnerable in the “guid” parameter. This allows an attacker to execute arbitrary commands on the WorkTime server as NT Authority\SYSTEM with the highest privileges. Attackers are able to access or manipulate sensitive data and take over the whole server.