CVE-2025-27926
📋 TL;DR
This vulnerability exposes passwords stored in configuration files within the K2 SmartForms Designer folder, making them readable by unauthorized users. It affects Nintex Automation versions 5.6 and 5.7 before 5.8, potentially compromising authentication credentials for systems using these configurations.
💻 Affected Systems
- Nintex Automation
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain administrative credentials, leading to complete system compromise, data theft, or lateral movement within the network.
Likely Case
Unauthorized users access sensitive configuration data, potentially obtaining credentials for integrated systems or databases.
If Mitigated
Limited exposure if proper access controls and network segmentation are already implemented.
🎯 Exploit Status
Exploitation requires access to the file system where configuration files are stored.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 5.8
Vendor Advisory: https://help.nintex.com/en-US/platform/ReleaseNotes/K2Five.htm
Restart Required: Yes
Instructions:
1. Backup current configuration. 2. Upgrade Nintex Automation to version 5.8 or later. 3. Restart the application services. 4. Verify that web.config files no longer contain plaintext passwords.
🔧 Temporary Workarounds
Restrict File System Access
windowsApply strict NTFS permissions to the K2 SmartForms Designer folder to prevent unauthorized read access.
icacls "C:\Program Files\K2\SmartForms\Designer" /deny "Users":(R)
Encrypt Configuration Sections
windowsUse ASP.NET configuration encryption to protect sensitive sections of web.config files.
aspnet_regiis -pef "connectionStrings" "C:\Program Files\K2\SmartForms\Designer" -prov "DataProtectionConfigurationProvider"
🧯 If You Can't Patch
- Implement strict access controls on the K2 SmartForms Designer folder to limit read permissions to authorized administrators only.
- Monitor file access attempts to the vulnerable configuration files using Windows audit policies.
🔍 How to Verify
Check if Vulnerable:
Check if Nintex Automation version is between 5.6 and 5.7, and examine web.config files in the K2 SmartForms Designer folder for plaintext passwords.Check Version:
Check the Nintex Automation version in the application's administrative interface or via the installed programs list in Windows.Verify Fix Applied:
After upgrading to version 5.8 or later, confirm that web.config files no longer contain readable passwords and that file permissions are properly restricted.📡 Detection & Monitoring
Log Indicators:
- Unusual file access events to web.config files in the K2 SmartForms Designer folder
- Failed authentication attempts using credentials that may have been exposed
Network Indicators:
- Unexpected connections from internal systems to databases or services using potentially compromised credentials
SIEM Query:
EventID=4663 AND ObjectName LIKE '%SmartForms\Designer\web.config%' AND Accesses='ReadData'