CVE-2026-1428
📋 TL;DR
CVE-2026-1428 is an OS command injection vulnerability in WellChoose's Single Sign-On Portal System that allows authenticated remote attackers to execute arbitrary operating system commands on the server. This vulnerability affects organizations using WellChoose's SSO portal software. Attackers can gain full control of affected servers through command execution.
💻 Affected Systems
- WellChoose Single Sign-On Portal System
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete server compromise leading to data exfiltration, lateral movement, ransomware deployment, or persistent backdoor installation.
Likely Case
Attacker gains shell access to the server, accesses sensitive data, and potentially pivots to other internal systems.
If Mitigated
Limited impact due to network segmentation, minimal privileges, and command execution restrictions.
🎯 Exploit Status
Exploitation requires authenticated access but command injection is straightforward once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.2.1
Vendor Advisory: https://www.twcert.org.tw/en/cp-139-10655-59160-2.html
Restart Required: Yes
Instructions:
1. Download version 4.2.1 from WellChoose vendor portal. 2. Backup current configuration and data. 3. Stop SSO portal service. 4. Install the update. 5. Restart the service. 6. Verify functionality.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject any user input containing shell metacharacters
# Example for Linux: Add input validation in application code
# Reject inputs containing: ; & | ` $ ( ) < > [ ] { } ' " \n \r \t
Network Segmentation
linuxIsolate SSO portal server from critical systems and restrict outbound connections
# Example iptables rules for Linux:
iptables -A OUTPUT -p tcp --dport 22 -j DROP
iptables -A OUTPUT -p tcp --dport 445 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate the SSO portal from other critical systems
- Apply principle of least privilege to the SSO portal service account and implement command execution restrictions
🔍 How to Verify
Check if Vulnerable:
Check SSO portal version via admin interface or configuration files. Versions below 4.2.1 are vulnerable.Check Version:
Check admin dashboard or configuration file for version numberVerify Fix Applied:
Verify version is 4.2.1 or higher and test input validation by attempting to inject test commands (in a controlled manner).📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns in system logs
- Multiple failed authentication attempts followed by successful login and command execution
- Suspicious process creation from SSO portal service account
Network Indicators:
- Unexpected outbound connections from SSO portal server
- SSH or other remote access attempts originating from SSO portal
SIEM Query:
source="sso-portal-logs" AND (command="*;*" OR command="*|*" OR command="*`*" OR command="*$(*")