CVE-2025-56385: WellSky Harmony SQLi Vulnerability

CVE-2025-56385 Overview

A critical SQL injection vulnerability exists in the login functionality of WellSky Harmony version 4.1.0.2.83. The vulnerability is located within the xmHarmony.asp endpoint, where user-supplied input to the TXTUSERID parameter is not properly sanitized before being incorporated into a SQL query. This allows unauthenticated attackers to inject malicious SQL statements, potentially leading to authentication bypass, sensitive data leakage, or full system compromise of backend database contents.

Critical Impact
This SQL injection vulnerability enables unauthenticated attackers to bypass authentication controls, extract sensitive data from backend databases, and potentially achieve full system compromise through the login functionality of WellSky Harmony.

Affected Products

WellSky Harmony version 4.1.0.2.83

Discovery Timeline

2025-11-12 - CVE-2025-56385 published to NVD
2025-12-31 - Last updated in NVD database

Technical Details for CVE-2025-56385

Vulnerability Analysis

This vulnerability falls under CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), commonly known as SQL Injection. The core issue stems from the application's failure to properly validate and sanitize user input before incorporating it into database queries.

When a user submits login credentials through the xmHarmony.asp endpoint, the TXTUSERID parameter value is directly concatenated into the SQL query without proper parameterization or input filtering. This classic SQL injection pattern allows attackers to manipulate the query logic by injecting SQL metacharacters and additional query fragments.

The network-accessible nature of this vulnerability means attackers can exploit it remotely without requiring any prior authentication or user interaction. Successful exploitation can result in complete authentication bypass, allowing attackers to gain unauthorized access to the application. Beyond initial access, attackers may leverage the SQL injection to enumerate database schemas, extract sensitive patient or organizational data, modify database records, or potentially escalate to operating system command execution depending on database configuration.

Root Cause

The root cause is insufficient input validation and the use of dynamic SQL query construction in the authentication module. The TXTUSERID parameter is incorporated into SQL statements through string concatenation rather than using parameterized queries or prepared statements. This design flaw allows SQL metacharacters (such as single quotes, dashes, and semicolons) to break out of the intended query structure and execute attacker-controlled SQL commands.

Attack Vector

The attack is network-based, targeting the xmHarmony.asp login endpoint. An attacker can craft a malicious HTTP request containing SQL injection payloads in the TXTUSERID parameter. Common attack patterns include:

The attacker would submit specially crafted input in the username field that terminates the original query and appends additional SQL logic. For example, classic authentication bypass payloads using comment sequences or boolean logic manipulation can be used to return true conditions regardless of the actual credentials provided.

Once initial access is achieved, the attacker may employ UNION-based injection techniques to extract data from other database tables, time-based blind injection to enumerate database contents when direct output is not visible, or stacked queries to execute additional SQL statements including potential data modification or deletion commands. For detailed technical analysis, see the Machevalia SQL Injection Analysis.

Detection Methods for CVE-2025-56385

Indicators of Compromise

Unusual SQL error messages appearing in web server logs or application responses from the xmHarmony.asp endpoint
Authentication logs showing successful logins with malformed or suspicious username patterns
Database audit logs revealing unexpected queries, UNION SELECT statements, or information schema enumeration
Anomalous data access patterns indicating bulk extraction of database records

Detection Strategies

Deploy Web Application Firewalls (WAF) with SQL injection detection rulesets monitoring the xmHarmony.asp endpoint
Implement database activity monitoring to detect anomalous query patterns, particularly those involving UNION operations or system table access
Configure intrusion detection systems to alert on common SQL injection payload signatures in HTTP POST data
Enable verbose logging on the WellSky Harmony application and correlate authentication events with database query logs

Monitoring Recommendations

Monitor HTTP request logs for SQL metacharacters (single quotes, double dashes, semicolons) in the TXTUSERID parameter
Set up alerts for database errors indicating syntax violations or unexpected query termination
Track failed and successful authentication attempts, flagging accounts with unusual login patterns
Implement network traffic analysis to detect data exfiltration patterns from database servers

How to Mitigate CVE-2025-56385

Immediate Actions Required

Contact WellSky support to inquire about available security patches or hotfixes for Harmony version 4.1.0.2.83
Restrict network access to the WellSky Harmony application to trusted IP ranges using firewall rules
Deploy a Web Application Firewall (WAF) with SQL injection protection rules in front of the application
Enable detailed logging on both the web server and database to aid in detecting exploitation attempts
Review database user permissions to ensure the application account has minimal required privileges

Patch Information

At the time of publication, no vendor advisory or official patch information has been released. Organizations should monitor WellSky Security Insights for updates and contact WellSky support directly for remediation guidance.

Workarounds

Implement network segmentation to isolate the WellSky Harmony server from direct internet access
Deploy an application-aware firewall or WAF configured to block SQL injection patterns targeting the TXTUSERID parameter
Consider implementing additional authentication layers such as VPN requirements or IP allowlisting
If possible, disable external access to the xmHarmony.asp endpoint until a patch is available

bash

# Example WAF rule configuration to block SQL injection attempts
# Add to your WAF configuration to protect the vulnerable endpoint
SecRule ARGS:TXTUSERID "@detectSQLi" \
    "id:1001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt blocked in TXTUSERID parameter',\
    tag:'CVE-2025-56385'"