CVE-2020-5349
📋 TL;DR
Dell EMC Networking S4100 and S5200 Series Switches manufactured before February 2020 contain hardcoded administrative credentials. Remote attackers can exploit this to gain full administrative control without authentication. Organizations using these switches in vulnerable configurations are affected.
💻 Affected Systems
- Dell EMC Networking S4100 Series Switches
- Dell EMC Networking S5200 Series Switches
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete network compromise - attacker gains administrative access to switches, enabling traffic interception, network disruption, lateral movement to other systems, and persistent backdoor installation.
Likely Case
Unauthorized administrative access leading to network configuration changes, traffic monitoring, denial of service, and potential data exfiltration.
If Mitigated
Limited impact if switches are isolated in secure network segments with strict access controls, though credential exposure remains a risk.
🎯 Exploit Status
Exploitation requires only knowledge of the hardcoded credentials and network access to the switch management interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates available - refer to Dell advisory for specific versions
Vendor Advisory: https://www.dell.com/support/article/en-us/sln320599/dsa-2020-074-dell-networking-security-update-for-a-hardcoded-credential-vulnerability
Restart Required: Yes
Instructions:
1. Identify affected switches using serial numbers/manufacturing dates. 2. Download latest firmware from Dell support site. 3. Backup current configuration. 4. Apply firmware update following Dell's upgrade procedures. 5. Verify update and restore configuration if needed.
🔧 Temporary Workarounds
Network Segmentation
allIsolate switch management interfaces from untrusted networks
Access Control Lists
allImplement strict ACLs to limit access to switch management interfaces
ip access-list standard MGMT-ACL
permit host [trusted_management_ip]
deny any
interface vlan [management_vlan]
ip access-group MGMT-ACL in
🧯 If You Can't Patch
- Immediately isolate affected switches from internet and untrusted networks
- Implement strict network segmentation and firewall rules to limit access to management interfaces
🔍 How to Verify
Check if Vulnerable:
Check switch serial number/manufacturing date against Dell's advisory. Switches manufactured before February 2020 are vulnerable.Check Version:
show versionVerify Fix Applied:
Verify firmware version is updated to post-February 2020 release and check that hardcoded credentials no longer work.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful login
- Unusual administrative access from unexpected IP addresses
- Configuration changes from unknown users
Network Indicators:
- Unexpected SSH/Telnet connections to switch management interfaces
- Traffic patterns indicating switch configuration changes
SIEM Query:
source="switch_logs" (event_type="authentication" AND result="success") AND user="[hardcoded_username]"