CVE-2021-21507
📋 TL;DR
Dell networking devices with vulnerable firmware versions use weak password encryption, allowing remote attackers to decrypt stored credentials. This affects Dell EMC Networking X-Series and PowerEdge VRTX Switch Module users who haven't updated to patched firmware versions. Attackers can potentially gain unauthorized access with compromised account privileges.
💻 Affected Systems
- Dell EMC Networking X-Series
- Dell EMC PowerEdge VRTX Switch Module
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with administrative privileges leading to network takeover, data exfiltration, and lateral movement to connected systems.
Likely Case
Unauthorized access to network devices, configuration changes, traffic interception, and potential credential reuse attacks against other systems.
If Mitigated
Limited impact with proper network segmentation, credential rotation, and monitoring in place.
🎯 Exploit Status
Attack requires remote access to device but no authentication. Exploitation likely involves retrieving and decrypting stored credentials.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: X-Series: 3.0.1.8+, VRTX Switch Module: 2.0.0.82+
Vendor Advisory: https://www.dell.com/support/kbdoc/000185252
Restart Required: Yes
Instructions:
1. Download updated firmware from Dell support site. 2. Backup current configuration. 3. Upload and install firmware update via management interface. 4. Reboot device. 5. Verify firmware version.
🔧 Temporary Workarounds
Network Segmentation
allRestrict management interface access to trusted networks only
Credential Rotation
allChange all passwords on affected devices
🧯 If You Can't Patch
- Isolate affected devices in separate VLAN with strict access controls
- Implement multi-factor authentication for management access if supported
🔍 How to Verify
Check if Vulnerable:
Check firmware version via CLI: 'show version' or web interface system informationCheck Version:
show versionVerify Fix Applied:
Confirm firmware version is 3.0.1.8 or higher for X-Series, 2.0.0.82 or higher for VRTX Switch Module📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts from new IPs
- Configuration changes from unexpected sources
- Multiple login attempts
Network Indicators:
- Unusual management interface traffic
- Connections from unexpected IP ranges to management ports
SIEM Query:
source="dell-switch" AND (event_type="authentication_failure" OR event_type="configuration_change")