CVE-2025-13818: ESET Management Agent Privilege Escalation

CVE-2025-13818 Overview

CVE-2025-13818 is a local privilege escalation vulnerability affecting the ESET Management Agent for Windows. The vulnerability stems from insecure handling of temporary batch file execution, which can be exploited by a local attacker with high privileges to escalate their access and compromise system confidentiality and integrity.

Critical Impact

Local attackers can exploit a Time-of-Check Time-of-Use (TOCTOU) race condition in the ESET Management Agent to escalate privileges, potentially gaining unauthorized access to sensitive data and the ability to modify critical system components.

Affected Products

• ESET Management Agent for Windows (versions prior to the security patch)

Discovery Timeline

• 2026-02-06 - CVE-2025-13818 published to NVD
• 2026-02-06 - Last updated in NVD database

Technical Details for CVE-2025-13818

Vulnerability Analysis

This vulnerability is classified under CWE-367 (Time-of-Check Time-of-Use Race Condition). The flaw exists in how the ESET Management Agent handles temporary batch files during execution. The agent creates temporary batch files that are subsequently executed with elevated privileges, but the window between file creation and execution creates an exploitable race condition.

An attacker with local access and high-level privileges can exploit this TOCTOU vulnerability by replacing or modifying the temporary batch file after it has been validated but before it is executed. This allows the attacker to inject malicious commands that will be executed with the elevated privileges of the ESET Management Agent service.

The local attack vector requires the attacker to have existing access to the target system. The vulnerability does not impact system availability, but successful exploitation leads to high impact on both confidentiality and integrity of the affected system.

Root Cause

The root cause is a Time-of-Check Time-of-Use (TOCTOU) race condition in the temporary batch file handling mechanism of the ESET Management Agent. The agent performs security checks on the batch file at one point in time but then executes it at a later point, creating a window during which the file can be manipulated by an attacker.

Attack Vector

The attack requires local access to the system where ESET Management Agent is installed. An attacker must monitor for the creation of temporary batch files by the agent, then quickly replace or modify the file content between the validation check and execution phase. The attacker needs high privileges to access the relevant file system locations where temporary files are created.

The exploitation involves:

1. Monitoring the temporary directory used by ESET Management Agent for batch file creation
2. Detecting when a new batch file is created and validated
3. Rapidly replacing or modifying the batch file content with malicious commands
4. The malicious commands execute with the elevated privileges of the agent service

For detailed technical information about this vulnerability, refer to the ESET Customer Advisory.

Detection Methods for CVE-2025-13818

Indicators of Compromise

• Unusual modification timestamps on temporary batch files in the ESET Management Agent temporary directories
• Rapid file creation and modification events in the agent's working directories
• Unexpected processes spawned as child processes of the ESET Management Agent service
• Anomalous file system access patterns targeting temporary directories

Detection Strategies

• Monitor file system events for rapid read/write operations on batch files in ESET Management Agent directories
• Implement file integrity monitoring on directories used by the ESET Management Agent for temporary file operations
• Configure endpoint detection to alert on suspicious batch file executions spawned from the ESET service context
• Review Windows Security Event Logs for privilege escalation indicators and unusual service behaviors

Monitoring Recommendations

• Enable advanced auditing on file system access for ESET Management Agent directories
• Deploy behavioral analysis to detect TOCTOU attack patterns such as rapid file modifications
• Monitor process creation events for unexpected command execution with elevated privileges
• Establish baseline behavior for ESET Management Agent operations to identify anomalies

How to Mitigate CVE-2025-13818

Immediate Actions Required

• Apply the latest security patch from ESET for the Management Agent immediately
• Review systems running ESET Management Agent for signs of compromise
• Restrict local access to systems where ESET Management Agent is installed
• Monitor for exploitation attempts while preparing to deploy patches

Patch Information

ESET has released a security patch addressing this vulnerability. System administrators should update the ESET Management Agent for Windows to the latest available version. For detailed patching instructions and affected version information, refer to the ESET Customer Advisory.

Workarounds

• Limit local access to systems running ESET Management Agent to trusted administrators only
• Implement strict file system permissions on temporary directories used by the agent
• Enable enhanced monitoring on endpoints running ESET products until patches can be applied
• Consider isolating critical systems running vulnerable versions until updates are deployed