1. Introduction
Cisco Firepower Enumeration refers to the ability to identify a network security application running on a remote device. This can allow attackers to gather information about the target environment, potentially leading to further exploitation of known vulnerabilities. Systems affected are typically those running Cisco Firepower, which includes IDS, firewall and routing capabilities. A successful exploit could lead to information disclosure, denial of service or potential compromise of the system.
2. Technical Explanation
Cisco Firepower devices expose identifiable characteristics through network communication. This allows attackers to determine the presence and potentially the version of the software running on the device. Expert privileges are required to check installed hotfixes, which can hinder timely patching. An attacker could use this information to search for publicly known vulnerabilities associated with the identified Cisco Firepower version and attempt exploitation.
- Root cause: The network security application exposes identifiable characteristics during normal operation.
- Exploit mechanism: An attacker scans the network, identifies a Cisco Firepower device, determines its software version, then searches for known vulnerabilities.
- Scope: Cisco Firepower devices running IDS, firewall and routing capabilities are affected.
3. Detection and Assessment
To confirm whether a system is vulnerable, first identify if Cisco Firepower is running on the device. Then determine its version to check for known vulnerabilities.
- Quick checks: Use network scanning tools to identify open ports and services associated with Cisco Firepower.
- Scanning: Nessus vulnerability scanner can be used with plugin ID 17ea494 to detect the presence of Cisco Firepower. This is an example only.
- Logs and evidence: Review firewall logs for communication patterns typical of Cisco Firepower devices.
nmap -sV 4. Solution / Remediation Steps
4.1 Preparation
- No services need to be stopped for this remediation.
4.2 Implementation
- Step 1: Check for and install the latest hotfixes and security patches available from Cisco. Refer to the Cisco Security Advisories website for current releases.
- Step 2: Ensure that the Cisco Firepower device is running a supported version of the software. Upgrade if necessary.
4.3 Config or Code Example
Before
Software Version: After
Software Version: 4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this vulnerability type. Regular patching is essential for addressing known vulnerabilities. Least privilege reduces the impact if a system is compromised.
- Practice 1: Patch cadence – Regularly apply security patches and updates to all systems, including Cisco Firepower devices.
- Practice 2: Least privilege – Limit user access to only the necessary resources and permissions on the Cisco Firepower device.
4.5 Automation (Optional)
Automation is not directly applicable for this vulnerability but can be used to schedule regular patch checks.
# Example PowerShell script to check software version (requires appropriate modules installed)
Get-CiscoFirepowerVersion | Where-Object {$_.Version -lt "latest_version"}5. Verification / Validation
Confirm the fix by verifying that the latest hotfixes are installed and the system is running a supported version of Cisco Firepower software. Re-run the detection methods to ensure the vulnerability is no longer present.
- Post-fix check: Use network scanning tools or the Cisco Firepower CLI to confirm the software version has been updated.
- Re-test: Run Nessus plugin ID 17ea494 again and verify that it does not report the vulnerability.
- Smoke test: Verify basic firewall functionality, such as internet access and internal network connectivity.
nmap -sV 6. Preventive Measures and Monitoring
- Baselines: Update a security baseline or policy to require the latest Cisco Firepower software versions.
- Pipelines: Add vulnerability scanning to CI or deployment pipelines to detect known vulnerabilities in Cisco Firepower configurations.
- Asset and patch process: Implement a regular patch review cycle for all systems, including Cisco Firepower devices.
7. Risks, Side Effects, and Roll Back
- Risk or side effect 1: Updates can sometimes introduce new bugs or compatibility problems.
- Risk or side effect 2: Service interruptions during the update process are possible.
8. References and Resources
Links to official advisories and trusted documentation related to this vulnerability.
- Vendor advisory or bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-2017-0605
- NVD or CVE entry: http://www.nessus.org/u?e17ea494