CVE-2021-20527
📋 TL;DR
CVE-2021-20527 is an improper neutralization of special elements vulnerability in IBM Resilient SOAR that allows a privileged user to create malicious scripts that could be executed with another user's permissions. This affects IBM Resilient SOAR V38.0 installations where privileged users have script creation capabilities.
💻 Affected Systems
- IBM Resilient SOAR
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
A malicious privileged user could execute arbitrary code with elevated privileges, potentially leading to complete system compromise, data exfiltration, or lateral movement within the environment.
Likely Case
Privileged users could escalate their privileges or impersonate other users to bypass access controls and perform unauthorized actions within the SOAR platform.
If Mitigated
With proper access controls and monitoring, the impact is limited to authorized users misusing their legitimate privileges within defined boundaries.
🎯 Exploit Status
Exploitation requires authenticated privileged access. The vulnerability involves improper input validation in script handling functionality.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: V38.0.1 and later
Vendor Advisory: https://www.ibm.com/support/pages/node/6444747
Restart Required: Yes
Instructions:
1. Download the IBM Resilient SOAR V38.0.1 or later update from IBM Fix Central. 2. Follow IBM's upgrade documentation for your deployment type (on-premises or cloud). 3. Apply the update following IBM's installation procedures. 4. Restart the Resilient SOAR services.
🔧 Temporary Workarounds
Restrict Script Creation Permissions
allTemporarily remove script creation capabilities from all non-essential privileged users until patching can be completed.
Implement Script Review Process
allRequire all scripts to be reviewed and approved by security administrators before deployment.
🧯 If You Can't Patch
- Implement strict least-privilege access controls for all user accounts
- Enable comprehensive logging and monitoring of all script creation and execution activities
🔍 How to Verify
Check if Vulnerable:
Check the IBM Resilient SOAR version via the web interface or by examining the installation directory. If version is exactly V38.0, the system is vulnerable.Check Version:
Check the version in the Resilient SOAR web interface under Administration > System SettingsVerify Fix Applied:
Verify the version has been updated to V38.0.1 or later through the web interface or system administration tools.📡 Detection & Monitoring
Log Indicators:
- Unusual script creation activities
- Script execution with unexpected user contexts
- Multiple script modifications in short timeframes
Network Indicators:
- Unusual API calls to script management endpoints
- Abnormal patterns in SOAR platform communications
SIEM Query:
source="resilient_soar" AND (event_type="script_create" OR event_type="script_execute") | stats count by user, script_name