Privilege escalation in Nestersoft Worktime
CVE-2025-15561
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.
Vulnerability class: Privilege Escalation
EPSS: 0.001 (1.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Nestersoft Worktime
- Nestersoft Inc. Worktime (On-prem/cloud) — versions <= 11.8.8
Weakness classification (CWE)
References
- 551230f0-3615-47bd-b7cc-93e92e730bbf (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2025-15561?
- CVE-2025-15561 is a high-severity vulnerability in Nestersoft Worktime, classified under Improper Privilege Management. CVSS score: 7.8/10. Published 2026-02-19.
- How severe is CVE-2025-15561?
- High severity. CVSS v3 base score is 7.8 out of 10.