CVE-2023-20223 - Cisco DNA Center API Vulnerability Allows Unauthorized Data Access and Modification

In April 2023, a serious vulnerability—CVE-2023-20223—was reported in Cisco DNA Center. This flaw can allow a remote, unauthenticated attacker to read and change sensitive data belonging to internal services by exploiting weak access controls in certain API requests. Here’s a clear explanation of what this vulnerability is, how attackers can exploit it, and what defenders should do to mitigate the risk.

What Is Cisco DNA Center?

Cisco DNA Center is a centralized dashboard for managing, automating, and securing enterprise networks. Since it has broad control over the networking environment, any security bug in the system can put entire organizations at risk.

Technical Details

The flaw exists because Cisco DNA Center doesn't properly enforce access controls on certain API endpoints. This means that, instead of only allowing authorized users to make certain API calls, the system lets anyone—without authentication—craft requests that read or even *change* internal data.

The attacker finds an API endpoint that doesn’t check for authentication.

- Using simple tools like curl or Postman, the attacker crafts a request to access internal services’ repositories.

Real-World Exploitation: How an Attacker Can Break In

Let’s walk through an example of how a remote attacker might exploit this vulnerability. This code sample is for educational purposes only, demonstrating what defenders need to look out for.

# Attacker sends a crafted HTTP GET request to leak internal data
curl -sk -X GET "https://victim-dnac.example.com/api/internal/repository/data";

# Attacker modifies internal configuration using a crafted POST request
curl -sk -X POST "https://victim-dnac.example.com/api/internal/repository/update"; \
     -H "Content-Type: application/json" \
     -d '{"key":"filename","value":"evil_config"}'

What happens here?

- Since access control isn’t enforced on these endpoints, the attacker does not need a session token or credentials.

Data Theft: Attackers can steal data processed by internal DNA Center services.

- Data Tampering: Attackers could plant malicious configuration, paving the way for deeper intrusion or sabotage.

Original References

- Cisco Security Advisory on CVE-2023-20223
- NIST CVE Detail - CVE-2023-20223

1. Update DNA Center Immediately

Cisco has released patches—make sure your system is running version 2.2.3.5 or later.

2. Network Segmentation

Limit access to your DNA Center appliance from untrusted networks using internal firewalls.

3. Monitor API Requests

Set up logging and alerting for suspicious or unauthorized API calls. Check for any unusual access patterns.

4. Review API Endpoints

For all exposed network services, make sure strong authentication and authorization is in place.

Conclusion

CVE-2023-20223 isn’t just another bug—it's a powerful exploit that can let anyone on the internet tamper with your most sensitive network operations. It’s a clear reminder of the importance of secure defaults and access control in API design, especially in critical management products like Cisco DNA Center.

Patch today, monitor tomorrow, and always keep your network defense up to date.

Timeline

Published on: 09/27/2023 18:15:11 UTC
Last modified on: 10/02/2023 19:21:45 UTC