CVE-2025-15561: WorkTime Privilege Escalation Vulnerability

CVE-2025-15561 Overview

CVE-2025-15561 is a local privilege escalation vulnerability in the WorkTime monitoring daemon that allows an attacker to elevate privileges to NT Authority\SYSTEM. The vulnerability exists due to improper access controls on the C:\ProgramData\wta\ClientExe directory, which is writable by "Everyone". By placing a malicious executable named WTWatch.exe in this directory, an attacker can achieve code execution with SYSTEM-level privileges when the WorkTime monitoring daemon runs the file.

Critical Impact

Local attackers can escalate privileges to NT Authority\SYSTEM, gaining complete control over the affected Windows system.

Affected Products

• WorkTime monitoring software (specific versions unconfirmed)

Discovery Timeline

• 2026-02-19 - CVE CVE-2025-15561 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2025-15561

Vulnerability Analysis

This vulnerability is classified under CWE-269 (Improper Privilege Management). The core issue stems from the WorkTime monitoring daemon's update mechanism, which executes files from a directory with overly permissive access controls. The C:\ProgramData\wta\ClientExe directory allows write access to all users on the system, creating a trivial exploitation path for local privilege escalation.

When the WorkTime monitoring daemon performs update operations, it searches for and executes WTWatch.exe from this directory. Because no integrity verification or signature validation is performed on the executable, an attacker can drop a malicious payload with the expected filename and wait for the daemon to execute it with elevated privileges.

Root Cause

The root cause is improper privilege management combined with insecure file permissions. The C:\ProgramData\wta\ClientExe directory grants write permissions to "Everyone", violating the principle of least privilege. Additionally, the WorkTime daemon executes binaries from this location without validating their authenticity, integrity, or origin. This combination of weak file system ACLs and missing executable validation creates a direct path to SYSTEM-level compromise.

Attack Vector

The attack is local in nature, requiring an authenticated user with access to the target system. The attacker must:

1. Create or compile a malicious executable payload
2. Rename the payload to WTWatch.exe
3. Write the malicious file to C:\ProgramData\wta\ClientExe
4. Wait for the WorkTime monitoring daemon to execute the file, triggering code execution as NT Authority\SYSTEM

This attack requires minimal technical sophistication and can be performed by any user with local access to the system, regardless of their privilege level.

The vulnerability mechanism involves placing a malicious executable in a predictable, world-writable location. When the WorkTime monitoring daemon's update routine runs, it executes the attacker-controlled WTWatch.exe in a SYSTEM context. For additional technical details, refer to the SEC Consult security advisory.

Detection Methods for CVE-2025-15561

Indicators of Compromise

• Unexpected executable files appearing in C:\ProgramData\wta\ClientExe directory
• Modified or newly created WTWatch.exe files with unusual timestamps, sizes, or digital signatures
• Process creation events showing child processes spawned by the WorkTime daemon with suspicious behavior
• Anomalous network connections or file system activity originating from SYSTEM-level processes

Detection Strategies

• Monitor file creation and modification events in the C:\ProgramData\wta\ClientExe directory using Windows Security Event logs or EDR solutions
• Implement hash-based allowlisting for legitimate WTWatch.exe executables
• Deploy SentinelOne behavioral AI to detect privilege escalation attempts and unauthorized code execution in sensitive directories
• Configure alerts for process injection or suspicious child process spawning from the WorkTime daemon

Monitoring Recommendations

• Enable detailed file auditing on C:\ProgramData\wta\ClientExe via Group Policy or local security policy
• Use SentinelOne's file integrity monitoring to track changes to executable files in application directories
• Implement continuous monitoring for processes running as SYSTEM that spawn from untrusted or recently modified executables

How to Mitigate CVE-2025-15561

Immediate Actions Required

• Restrict permissions on C:\ProgramData\wta\ClientExe to remove write access for standard users and the "Everyone" group
• Audit existing files in the affected directory for unauthorized or suspicious executables
• Consider temporarily disabling the WorkTime monitoring daemon until patches are available or mitigations are applied
• Implement application control policies to prevent unauthorized executables from running in sensitive directories

Patch Information

No vendor patch information is currently available. Organizations should monitor the SEC Consult advisory page for updates regarding official fixes. Contact the WorkTime vendor directly for remediation guidance.

Workarounds

• Modify the ACLs on C:\ProgramData\wta\ClientExe to restrict write access to administrators only
• Deploy application whitelisting solutions such as Windows Defender Application Control (WDAC) or AppLocker to prevent execution of unauthorized binaries
• Utilize SentinelOne's endpoint protection to block malicious executable deployment and privilege escalation attempts
• Implement network segmentation to limit the impact of compromised systems

# PowerShell command to restrict directory permissions
icacls "C:\ProgramData\wta\ClientExe" /inheritance:r /grant:r "BUILTIN\Administrators:(OI)(CI)F" /grant:r "NT AUTHORITY\SYSTEM:(OI)(CI)F"