CVE-2021-34751
📋 TL;DR
This vulnerability allows authenticated low-privilege users to view sensitive configuration information in clear text through Cisco Firepower Management Center's web GUI. It affects Cisco FMC Software due to improper encryption of stored sensitive data. Attackers with valid credentials can access configuration parameters that should be protected.
💻 Affected Systems
- Cisco Firepower Management Center (FMC) Software
📦 What is this software?
Secure Firewall Management Center by Cisco
Secure Firewall Management Center by Cisco
Secure Firewall Management Center by Cisco
⚠️ Risk & Real-World Impact
Worst Case
Attackers obtain sensitive network configuration details, firewall rules, authentication credentials, or other protected information that could facilitate further attacks or network compromise.
Likely Case
Authorized but low-privileged users or compromised accounts access configuration details they shouldn't see, potentially learning about network architecture or security controls.
If Mitigated
With proper access controls and monitoring, impact is limited to information disclosure without direct system compromise.
🎯 Exploit Status
Exploitation requires valid credentials and GUI access. Attack involves navigating to specific configuration sections.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Cisco advisory for specific fixed versions
Vendor Advisory: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-infodisc-Ft2WVmNU
Restart Required: Yes
Instructions:
1. Review Cisco advisory for affected versions. 2. Download and apply appropriate software update from Cisco. 3. Restart FMC services or appliance as required.
🔧 Temporary Workarounds
No workarounds available
allCisco states there are no workarounds that address this vulnerability
🧯 If You Can't Patch
- Restrict access to FMC GUI to only authorized administrators using network segmentation
- Implement strict credential management and monitoring for FMC access
🔍 How to Verify
Check if Vulnerable:
Check FMC software version against affected versions listed in Cisco advisoryCheck Version:
From FMC CLI: 'show version' or check via GUI under System > UpdatesVerify Fix Applied:
Verify FMC software version is updated to fixed version listed in Cisco advisory📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to configuration sections
- Multiple failed login attempts followed by successful access
Network Indicators:
- Unauthorized access to FMC web interface from unexpected sources
SIEM Query:
source="fmc.logs" AND (event_type="configuration_access" OR user_privilege="low") AND resource="sensitive_config"