CVE-2025-59710: Kovai Biztalk360 RCE Vulnerability

CVE-2025-59710 Overview

CVE-2025-59710 is a remote code execution vulnerability in Kovai Biztalk360 prior to version 11.5. The vulnerability stems from incorrect access control that allows any authenticated user to request the loading of a DLL file. During the loading process, a method within the DLL is automatically called, enabling an attacker to craft a malicious DLL, upload it to the server, and achieve full remote code execution on the target system.

Critical Impact

This vulnerability allows any domain account user to achieve remote code execution on the Biztalk360 server, potentially leading to complete system compromise, data exfiltration, and lateral movement within the network.

Affected Products

• Kovai Biztalk360 versions prior to 11.5
• All installations with default access control configurations

Discovery Timeline

• 2026-04-03 - CVE-2025-59710 published to NVD
• 2026-04-09 - Last updated in NVD database

Technical Details for CVE-2025-59710

Vulnerability Analysis

This vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) and represents a severe access control flaw in the Biztalk360 application. The core issue lies in the application's failure to properly restrict which users can request DLL loading operations.

Biztalk360 is a monitoring and management tool for Microsoft BizTalk Server environments. The affected functionality appears to allow users to trigger the loading of DLL files, presumably for extensibility or plugin purposes. However, due to insufficient access control validation, this capability is available to any authenticated user within the domain, regardless of their intended privilege level.

The attack chain requires an attacker to first upload a malicious DLL to a location accessible by the Biztalk360 server, then trigger the DLL loading mechanism. When the application loads the malicious DLL, it automatically invokes a method within the library, executing the attacker's arbitrary code with the privileges of the Biztalk360 application service account.

Root Cause

The root cause is incorrect access control implementation in the DLL loading functionality of Biztalk360. The application fails to enforce proper authorization checks before allowing users to request DLL loading operations. This represents a broken access control vulnerability where privileged functionality is exposed to users who should not have access to it.

Additionally, the application does not appear to validate or restrict which DLL files can be loaded, allowing attacker-controlled malicious libraries to be processed.

Attack Vector

The attack is network-based and requires user interaction (likely social engineering or credential compromise to obtain domain account access). An attacker with any valid domain account credentials can:

1. Authenticate to the Biztalk360 application
2. Upload a malicious DLL to a server-accessible location (or leverage existing file upload functionality)
3. Trigger the DLL loading mechanism through the vulnerable endpoint
4. Achieve code execution when the application loads and invokes methods from the malicious DLL

The vulnerability allows remote exploitation without requiring elevated privileges within the Biztalk360 application itself. For detailed technical analysis, refer to the Synacktiv Security Advisory.

Detection Methods for CVE-2025-59710

Indicators of Compromise

• Unusual DLL files appearing in Biztalk360 installation or temporary directories
• Unexpected process spawning from Biztalk360 application processes
• Anomalous network connections originating from the Biztalk360 server
• Authentication logs showing access from unexpected domain accounts followed by privileged operations

Detection Strategies

• Monitor file system activity for new DLL files written to Biztalk360 directories
• Implement application-level logging to track DLL loading requests and the requesting user accounts
• Deploy endpoint detection and response (EDR) solutions to identify malicious code execution patterns
• Audit authentication events for unusual access patterns to the Biztalk360 application

Monitoring Recommendations

• Enable verbose logging within Biztalk360 to capture all user actions and system operations
• Configure SIEM alerts for file creation events involving DLL files in monitored directories
• Implement network segmentation monitoring to detect lateral movement attempts from compromised Biztalk360 servers
• Regularly review access logs for the Biztalk360 application to identify unauthorized access attempts

How to Mitigate CVE-2025-59710

Immediate Actions Required

• Upgrade Kovai Biztalk360 to version 11.5 or later immediately
• Restrict network access to the Biztalk360 application to only necessary administrative users
• Review and audit all domain accounts with access to Biztalk360 and revoke unnecessary permissions
• Monitor Biztalk360 servers for signs of compromise pending the upgrade

Patch Information

Kovai has addressed this vulnerability in Biztalk360 version 11.5. Organizations running versions prior to 11.5 should upgrade immediately to remediate the remote code execution risk. The upgrade implements proper access control checks for DLL loading functionality and restricts this capability to appropriately privileged users.

For additional details on the vulnerability, see the Synacktiv Security Advisory.

Workarounds

• Implement network-level access controls to restrict access to Biztalk360 to only trusted administrator workstations
• Deploy Web Application Firewall (WAF) rules to block suspicious requests targeting DLL loading endpoints
• Disable any unused extensibility or plugin features that may expose DLL loading functionality
• Implement application whitelisting on the Biztalk360 server to prevent unauthorized DLL execution

# Example: Restrict network access to Biztalk360 using Windows Firewall
netsh advfirewall firewall add rule name="Restrict Biztalk360 Access" dir=in action=block protocol=tcp localport=443 remoteip=any
netsh advfirewall firewall add rule name="Allow Biztalk360 Admin Subnet" dir=in action=allow protocol=tcp localport=443 remoteip=10.0.1.0/24