CVE-2025-59711: Kovai Biztalk360 Path Traversal Flaw

CVE-2025-59711 Overview

CVE-2025-59711 is a Directory Traversal vulnerability discovered in Kovai BizTalk360 versions prior to 11.5. The vulnerability exists due to improper handling of user-provided input within an upload mechanism, allowing an authenticated attacker to write files outside of the intended destination directory. Additionally, this flaw can be leveraged to coerce authentication from the service, potentially leading to remote code execution from any domain account.

Critical Impact

Authenticated attackers can leverage this directory traversal vulnerability to write arbitrary files to locations outside the designated upload directory, potentially enabling remote code execution or unauthorized access to sensitive system resources.

Affected Products

• Kovai BizTalk360 versions prior to 11.5

Discovery Timeline

• 2026-04-03 - CVE CVE-2025-59711 published to NVD
• 2026-04-09 - Last updated in NVD database

Technical Details for CVE-2025-59711

Vulnerability Analysis

This vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), commonly known as Path Traversal or Directory Traversal. The flaw resides in BizTalk360's file upload mechanism, which fails to properly sanitize user-supplied input before using it to construct file paths.

When a user uploads a file through the vulnerable endpoint, the application does not adequately validate or sanitize the filename or path components. An attacker with valid authentication credentials can craft malicious requests containing path traversal sequences (such as ../ or ..\) to escape the intended upload directory and write files to arbitrary locations on the server's file system.

The vulnerability can also be exploited to coerce authentication from the service, as documented in the Synacktiv Security Advisory. This authentication coercion could be chained with other techniques to achieve remote code execution from any domain account with access to the BizTalk360 application.

Root Cause

The root cause of this vulnerability is insufficient input validation in the file upload functionality. The application fails to:

1. Properly sanitize path traversal sequences from user-supplied filenames
2. Validate that the resulting file path remains within the intended upload directory
3. Implement proper canonicalization of file paths before writing files to disk

This allows malicious path components to be processed, enabling attackers to traverse the directory structure and place files in unauthorized locations.

Attack Vector

The attack vector is network-based and requires authentication to the BizTalk360 application. An attacker with valid credentials can exploit this vulnerability by:

1. Authenticating to the BizTalk360 web interface
2. Accessing the vulnerable upload functionality
3. Crafting a malicious request with path traversal sequences embedded in the filename or path parameter
4. Uploading a file that gets written to an arbitrary location outside the intended directory

The vulnerability can be exploited remotely over the network with low attack complexity. The attacker needs only low-level privileges (authenticated user) and no user interaction is required to successfully exploit this flaw. Successful exploitation can result in high impact to both confidentiality and integrity of the system.

Detection Methods for CVE-2025-59711

Indicators of Compromise

• Unusual file creation events in directories outside the designated BizTalk360 upload folder
• HTTP requests to upload endpoints containing path traversal sequences such as ../, ..\, or URL-encoded variants like %2e%2e%2f
• Unexpected authentication attempts or NTLM relay activity originating from the BizTalk360 service account
• Web server logs showing malformed or suspicious upload requests with directory escape patterns

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block requests containing path traversal patterns in upload parameters
• Monitor file system activity for file creation operations outside expected directories by the BizTalk360 application process
• Review authentication logs for unusual coerced authentication events from the service account
• Deploy endpoint detection rules that alert on path traversal exploitation attempts targeting known vulnerable endpoints

Monitoring Recommendations

• Enable detailed logging for all file upload operations in BizTalk360 and forward logs to a SIEM platform
• Configure file integrity monitoring (FIM) on critical system directories to detect unauthorized file writes
• Monitor network traffic for suspicious NTLM authentication flows that may indicate credential coercion attempts
• Regularly audit user accounts with access to BizTalk360 to identify any potentially compromised credentials

How to Mitigate CVE-2025-59711

Immediate Actions Required

• Upgrade Kovai BizTalk360 to version 11.5 or later, which addresses this vulnerability
• Restrict network access to BizTalk360 management interfaces to trusted IP ranges only
• Audit user accounts with access to BizTalk360 and remove unnecessary privileges
• Review file system permissions to limit the impact of potential arbitrary file writes

Patch Information

Kovai has addressed this vulnerability in BizTalk360 version 11.5. Organizations running affected versions should prioritize upgrading to the patched release. For detailed technical information about this vulnerability, refer to the Synacktiv Security Advisory.

Workarounds

• Implement strict network segmentation to limit access to BizTalk360 only from authorized management networks
• Deploy a web application firewall (WAF) with rules configured to block path traversal sequences in HTTP requests
• Restrict file system permissions for the BizTalk360 service account to only the directories required for normal operation
• Monitor and alert on any file creation events outside expected upload directories as an interim detection measure