CVE-2021-36314
📋 TL;DR
Dell EMC CloudLink versions 7.1 and earlier contain an arbitrary file creation vulnerability that allows remote unauthenticated attackers to create arbitrary files on the system. This could lead to remote code execution if combined with other vulnerabilities or misconfigurations. All users of CloudLink 7.1 and prior versions are affected.
💻 Affected Systems
- Dell EMC CloudLink
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote unauthenticated attacker gains full system control through arbitrary file creation leading to remote code execution, potentially compromising the entire CloudLink environment and connected systems.
Likely Case
Attackers create malicious files that could be executed through other means, leading to partial system compromise, data theft, or lateral movement within the network.
If Mitigated
With proper network segmentation and access controls, impact is limited to the CloudLink system itself without affecting other critical infrastructure.
🎯 Exploit Status
The vulnerability allows unauthenticated remote exploitation, making it particularly dangerous. No public exploit code was found at time of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 7.1.1 or later (check Dell advisory for exact version)
Vendor Advisory: https://www.dell.com/support/kbdoc/en-us/000193031/https-dellservices-lightning-force-com-one-one-app
Restart Required: Yes
Instructions:
1. Review Dell advisory DSA-2021-205. 2. Download and apply the latest CloudLink update from Dell support portal. 3. Restart the CloudLink service or appliance as required. 4. Verify the update was successful.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to CloudLink management interfaces to trusted IP addresses only
Use firewall rules to limit access: iptables -A INPUT -p tcp --dport [CloudLink_port] -s [trusted_ips] -j ACCEPT
iptables -A INPUT -p tcp --dport [CloudLink_port] -j DROP
🧯 If You Can't Patch
- Isolate CloudLink systems in a dedicated network segment with strict firewall rules
- Implement network monitoring and intrusion detection specifically for CloudLink traffic
🔍 How to Verify
Check if Vulnerable:
Check CloudLink version via web interface or CLI. If version is 7.1 or earlier, system is vulnerable.Check Version:
Check web interface admin panel or use CloudLink CLI command: cloudlink --versionVerify Fix Applied:
Verify CloudLink version is 7.1.1 or later after applying patch. Test that arbitrary file creation is no longer possible.📡 Detection & Monitoring
Log Indicators:
- Unusual file creation events in CloudLink logs
- Unauthenticated access attempts to file creation endpoints
- Abnormal process execution following file creation
Network Indicators:
- Unusual HTTP POST requests to file creation endpoints
- Traffic from unexpected sources to CloudLink management ports
SIEM Query:
source="cloudlink" AND (event_type="file_create" OR http_method="POST") AND src_ip NOT IN [trusted_ips]