How to remediate – Hunt CCTV DVR.cfg Direct Request Information Disclosure

1. Introduction

The Hunt CCTV DVR.cfg Direct Request Information Disclosure vulnerability allows an attacker to retrieve a device’s configuration file, ‘DVR.cfg’. This file contains sensitive information like credentials in plaintext. Successful exploitation could allow attackers to gain unauthorized access to the DVR system and potentially compromise connected networks. This affects Hunt CCTV digital video recorders. Confidentiality is at high risk due to credential exposure.

2. Technical Explanation

The vulnerability stems from a lack of authentication on the web server, allowing unauthenticated attackers to directly request the ‘DVR.cfg’ file. An attacker can simply send an HTTP request to retrieve this configuration file. CVE-2013-1391 describes this issue.

• Root cause: Missing authentication checks for accessing sensitive files like DVR.cfg.
• Exploit mechanism: An attacker sends a simple GET request to the web server requesting ‘/DVR.cfg’. For example, using curl: curl http://[target_ip]/DVR.cfg.
• Scope: Hunt CCTV DVR models are affected.

3. Detection and Assessment

You can confirm vulnerability by attempting to retrieve the ‘DVR.cfg’ file directly from a vulnerable device. A thorough assessment involves reviewing network traffic for requests to this file.

• Quick checks: Attempt to access the configuration file via a web browser or using curl: curl http://[target_ip]/DVR.cfg. If the file downloads, the system is likely vulnerable.
• Scanning: Nessus plugin ID 57579 can detect this vulnerability as an example.
• Logs and evidence: Web server access logs may show requests for ‘/DVR.cfg’ from unauthorized sources.

curl http://[target_ip]/DVR.cfg

4. Solution / Remediation Steps

Currently, there is no known official solution available at this time. Mitigation focuses on network segmentation and monitoring.

4.1 Preparation

• Stopping services is not required for initial assessment but may be needed for future mitigation attempts. A roll back plan involves restoring from backup or snapshot.
• Change windows are recommended due to potential service disruption. Approval should come from IT security and the system owner.

4.2 Implementation

1. Step 1: Monitor network traffic for unauthorized access attempts to ‘/DVR.cfg’.
2. Step 2: Implement network segmentation to isolate DVRs from sensitive networks.

4.3 Config or Code Example

There is no configuration change available at this time.

Before

N/A

After

N/A

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help reduce the risk of this vulnerability type.

• Practice 1: Least privilege – limit access to DVR systems and their configuration files.
• Practice 2: Network segmentation – isolate DVRs from critical networks to contain potential breaches.

4.5 Automation (Optional)

No automation is available at this time.

N/A

5. Verification / Validation

• Post-fix check: Attempt to access the configuration file via a web browser or curl. Access should be denied, resulting in an error message (e.g., 403 Forbidden).
• Re-test: Repeat the initial detection method (curl http://[target_ip]/DVR.cfg) and confirm that the file is no longer accessible.
• Monitoring: Monitor web server logs for access attempts to ‘/DVR.cfg’ and alert on any unauthorized activity.

curl http://[target_ip]/DVR.cfg

6. Preventive Measures and Monitoring

Update security baselines and policies to include requirements for secure DVR configuration and network segmentation. Consider adding checks in deployment pipelines.

• Baselines: Update a security baseline or policy to require authentication for accessing sensitive files on DVRs.
• Pipelines: Add checks in CI/CD pipelines to scan for open ports and vulnerable configurations on DVR systems.
• Asset and patch process: Implement a regular review cycle for DVR firmware updates and security patches.

7. Risks, Side Effects, and Roll Back

Network segmentation may impact remote access or video streaming functionality. Roll back involves restoring the original network configuration.

• Roll back: Restore the previous network configuration from backup or snapshot.

8. References and Resources

Refer to official advisories for accurate information about this vulnerability.

• Vendor advisory or bulletin: https://seclists.org/fulldisclosure/2013/Jan/246
• NVD or CVE entry: CVE-2013-1391
• Product or platform documentation relevant to the fix: N/A.