1. Introduction
The Cisco DNA Spaces Connector Web Detection vulnerability indicates that the web user interface for this connector is accessible on a remote host. This poses a risk as it potentially allows unauthorized access to configuration settings, requiring HTTP form credentials to retrieve version information. Affected systems are typically those running Cisco DNA Spaces and its associated connectors. A successful exploit could lead to information disclosure and potential compromise of the connected network. Confidentiality, integrity, and availability may be impacted if an attacker gains access to sensitive data or modifies system configurations.
2. Technical Explanation
The vulnerability stems from the presence of a publicly accessible web interface for the Cisco DNA Spaces Connector. This interface allows management of the connector but requires authentication. An attacker could attempt to brute-force credentials or exploit other vulnerabilities within the web application itself. The primary risk is unauthorized access to the connector’s configuration and potentially the underlying network it manages.
- Root cause: The web user interface for Cisco DNA Spaces Connector is exposed without sufficient restrictions.
- Exploit mechanism: An attacker attempts to access the web UI, then tries to gain access using default or guessed credentials.
- Scope: Systems running Cisco DNA Spaces Connector with a publicly accessible web interface are affected.
3. Detection and Assessment
To confirm vulnerability, check for the presence of the web interface on your network. A thorough assessment involves attempting to access the UI and identifying its version number.
- Quick checks: Use a web browser to navigate to the IP address or hostname of the Cisco DNA Spaces Connector. Look for a login page indicating the connector’s presence.
- Scanning: Nessus plugin ID 165239 can detect this vulnerability, but results should be verified manually.
- Logs and evidence: Review web server logs for access attempts to the connector’s interface (e.g., /dna/system/connector).
# Example command placeholder:
# Use nmap to scan for port 80 or 443 on the Cisco DNA Spaces Connector IP address.
nmap -p 80,443
4. Solution / Remediation Steps
The primary solution is to restrict access to the web interface and ensure strong authentication measures are in place.
4.1 Preparation
- Services: No services need to be stopped for this remediation.
- Roll back plan: Revert any firewall rule changes if connectivity issues arise.
4.2 Implementation
- Step 1: Configure the firewall to allow access to the Cisco DNA Spaces Connector web interface only from trusted IP addresses or networks.
- Step 2: Ensure strong passwords are used for all connector accounts and that multi-factor authentication is enabled if possible.
4.3 Config or Code Example
Before
# Firewall rule allowing access from any source IP address
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
After
# Firewall rule allowing access only from trusted IP address 192.168.1.100
iptables -A INPUT -s 192.168.1.100 -p tcp --dport 80 -j ACCEPT
4.4 Security Practices Relevant to This Vulnerability
Several security practices can help prevent this type of vulnerability. Least privilege is crucial, limiting access only to authorized users and networks. Input validation helps block malicious requests, and secure defaults minimize the attack surface.
- Practice 1: Implement least privilege by restricting network access to essential services only.
- Practice 2: Enforce strong password policies and multi-factor authentication for all administrative accounts.
4.5 Automation (Optional)
If using infrastructure as code, update firewall rules through your automation platform to restrict access to the connector’s web interface.
# Example Ansible snippet:
- name: Restrict access to Cisco DNA Spaces Connector Web UI
firewalld:
zone: public
rule:
port: 80/tcp
source: 192.168.1.100
permanent: true
state: enabled
5. Verification / Validation
Confirm the fix by verifying that access to the web interface is restricted to authorized IP addresses and networks. Test connectivity from a trusted source and confirm it works, then test from an untrusted source and verify it’s blocked.
- Post-fix check: Attempt to access the web UI from both a trusted and untrusted IP address. Verify that only the trusted IP can connect.
- Re-test: Re-run the initial network scan (nmap) from an untrusted source to confirm it cannot reach port 80 or 443.
- Smoke test: Ensure legitimate users can still access other connector functions, such as API calls or management interfaces.
- Monitoring: Monitor firewall logs for any unauthorized access attempts to the Cisco DNA Spaces Connector web interface.
# Post-fix command and expected output (example)
nmap -p 80
PORT STATE SERVICE
80/tcp filtered http
6. Preventive Measures and Monitoring
Update security baselines to include restrictions on web interface access. Implement checks in CI/CD pipelines to ensure firewall rules are correctly configured during deployment. A regular patch review cycle helps address vulnerabilities promptly.
- Baselines: Update your network security baseline to require restricted access for all web interfaces.
- Pipelines: Add a check to your infrastructure code pipeline to verify that the Cisco DNA Spaces Connector firewall rules are correctly configured.
- Asset and patch process: Implement a monthly review of security advisories and apply patches promptly.
7. Risks, Side Effects, and Roll Back
- Risk or side effect 1: Blocking legitimate user access due to overly restrictive firewall rules. Mitigation: Carefully test all changes and document the configuration.
- Roll back: Revert the firewall rule changes to their previous state if connectivity issues arise.
8. References and Resources
- Vendor advisory or bulletin: No specific vendor advisory found for this detection at the time of writing.
- NVD or CVE entry: No specific CVE associated with this detection, but related vulnerabilities may exist in Cisco DNA Spaces.
- Product or platform documentation relevant to the fix: Cisco DNA Spaces Documentation