CVE-2021-28588
📋 TL;DR
This vulnerability allows authenticated attackers to perform path traversal attacks via crafted HTTP POST requests in Adobe RoboHelp Server. Successful exploitation could lead to arbitrary code execution in the context of the current user. Organizations using Adobe RoboHelp Server version 2019.0.9 or earlier are affected.
💻 Affected Systems
- Adobe RoboHelp Server
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the RoboHelp Server process, potentially leading to data theft, lateral movement, or ransomware deployment.
Likely Case
Unauthorized file access, directory traversal, and potential remote code execution leading to server compromise.
If Mitigated
Limited impact with proper network segmentation, least privilege configuration, and monitoring in place.
🎯 Exploit Status
Exploitation requires authenticated access but is straightforward once credentials are obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2019.0.10 or later
Vendor Advisory: https://helpx.adobe.com/security/products/robohelp-server/apsb21-36.html
Restart Required: Yes
Instructions:
1. Download the latest patch from Adobe's website. 2. Backup your RoboHelp Server installation. 3. Apply the patch following Adobe's instructions. 4. Restart the RoboHelp Server service.
🔧 Temporary Workarounds
Network Segmentation
allRestrict access to RoboHelp Server to only trusted networks and users.
Authentication Hardening
allImplement strong authentication mechanisms and monitor for suspicious login attempts.
🧯 If You Can't Patch
- Implement strict network access controls to limit exposure
- Monitor for unusual HTTP POST requests to RoboHelp Server endpoints
🔍 How to Verify
Check if Vulnerable:
Check the RoboHelp Server version in the administration interface or installation directory.Check Version:
Check the version in RoboHelp Server admin panel or installation properties.Verify Fix Applied:
Verify the version is 2019.0.10 or later and test path traversal attempts are blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests with path traversal patterns (../ sequences)
- Multiple failed authentication attempts followed by successful login
Network Indicators:
- HTTP POST requests to RoboHelp Server with suspicious parameters
- Unexpected outbound connections from RoboHelp Server
SIEM Query:
source="robohelp.log" AND (http_method="POST" AND (uri="*../*" OR params="*../*"))