CVE-2021-32756
📋 TL;DR
CVE-2021-32756 is a critical remote code execution vulnerability in ManageIQ's MiqExpression module where low-privilege users can inject and execute arbitrary Ruby code. Successful exploitation allows attackers to gain root privileges on the host system. All ManageIQ users with versions prior to jansa-4, kasparov-2, or lasker-1 are affected.
💻 Affected Systems
- ManageIQ
📦 What is this software?
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
Manageiq by Manageiq
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root-level code execution, data exfiltration, lateral movement, and persistent backdoor installation.
Likely Case
Privilege escalation from low-privilege user to root, followed by data theft, system manipulation, or ransomware deployment.
If Mitigated
Limited impact through proper RBAC restrictions, but still potential for code execution within application context.
🎯 Exploit Status
Exploitation requires authenticated access but only low privileges. The vulnerability is in expression evaluation, making exploitation straightforward for attackers familiar with Ruby injection.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: jansa-4, kasparov-2, or lasker-1
Vendor Advisory: https://github.com/ManageIQ/manageiq/security/advisories/GHSA-32x4-vj4r-57rq
Restart Required: Yes
Instructions:
1. Backup your ManageIQ instance. 2. Upgrade to jansa-4, kasparov-2, or lasker-1 release. 3. Restart the ManageIQ service. 4. Verify the patch is applied by checking version.
🔧 Temporary Workarounds
RBAC Restriction
allRestrict user permissions via Role-Based Access Control to limit access to MiqExpression functionality
# Configure RBAC in ManageIQ admin interface to restrict expression editing capabilities
🧯 If You Can't Patch
- Implement strict RBAC policies to limit user access to only necessary application components
- Network segmentation to isolate ManageIQ instances and restrict access to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check ManageIQ version via admin interface or by examining the application version files. If version is older than jansa-4, kasparov-2, or lasker-1, the system is vulnerable.Check Version:
Check ManageIQ web interface admin panel or examine /var/www/miq/vmdb/VERSION fileVerify Fix Applied:
Verify the ManageIQ version shows jansa-4, kasparov-2, or lasker-1 or newer. Test expression functionality to ensure Ruby code injection is no longer possible.📡 Detection & Monitoring
Log Indicators:
- Unusual Ruby code execution in application logs
- Multiple failed expression validations from single user
- Unexpected system command execution in logs
Network Indicators:
- Unusual outbound connections from ManageIQ host
- Sudden increase in authentication attempts to ManageIQ
SIEM Query:
source="manageiq" AND ("MiqExpression" OR "expression evaluation") AND ("ruby_exec" OR "system(" OR "eval(")