CVE-2021-41828
📋 TL;DR
Zoho ManageEngine Remote Access Plus versions before 10.1.2121.1 contain hardcoded credentials in resetPWD.xml, allowing attackers to bypass authentication and gain unauthorized access. This affects all organizations using vulnerable versions of the Remote Access Plus software for remote desktop management.
💻 Affected Systems
- Zoho ManageEngine Remote Access Plus
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the ManageEngine Remote Access Plus system, allowing attackers to execute arbitrary commands, access sensitive systems managed through the platform, and pivot to internal networks.
Likely Case
Unauthorized access to the Remote Access Plus administrative interface, enabling attackers to view/manage connected systems, steal credentials, and deploy malware to managed endpoints.
If Mitigated
Limited impact with proper network segmentation and access controls, though the hardcoded credentials still represent a significant authentication bypass vulnerability.
🎯 Exploit Status
Exploitation is trivial - attackers can use the hardcoded credentials directly without any special tools or techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.2121.1 and later
Vendor Advisory: https://www.manageengine.com/remote-desktop-management/hotfix-readme.html
Restart Required: Yes
Instructions:
1. Download the latest version from ManageEngine website. 2. Backup current installation. 3. Run the installer to upgrade. 4. Restart the Remote Access Plus service. 5. Verify the version is 10.1.2121.1 or later.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to the Remote Access Plus web interface to trusted IP addresses only
File Removal (Temporary)
allRemove or rename the vulnerable resetPWD.xml file as a temporary measure
mv /path/to/resetPWD.xml /path/to/resetPWD.xml.bak
del C:\path\to\resetPWD.xml
🧯 If You Can't Patch
- Isolate the Remote Access Plus server from the internet and restrict internal access to only necessary users
- Implement additional authentication layers such as VPN or reverse proxy with strong authentication
🔍 How to Verify
Check if Vulnerable:
Check if the file resetPWD.xml exists in the installation directory and contains hardcoded credentialsCheck Version:
Check the version in the web interface under Help > About, or examine the build version in installation directoryVerify Fix Applied:
Verify the version is 10.1.2121.1 or later and that resetPWD.xml no longer contains hardcoded credentials📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful login using hardcoded credentials
- Unusual administrative actions from unexpected IP addresses
Network Indicators:
- HTTP requests to resetPWD.xml endpoint from unauthorized sources
- Unusual outbound connections from the Remote Access Plus server
SIEM Query:
source="manageengine" AND (event="authentication" AND result="success" AND user="hardcoded_user") OR (url="/resetPWD.xml")🔗 References
- https://medium.com/nestedif/vulnerability-disclosure-hardcoded-keys-password-zoho-r-a-p-318aa9bba2e
- https://www.manageengine.com/remote-desktop-management/hotfix-readme.html
- https://medium.com/nestedif/vulnerability-disclosure-hardcoded-keys-password-zoho-r-a-p-318aa9bba2e
- https://www.manageengine.com/remote-desktop-management/hotfix-readme.html
