1. Introduction
The remote host is an ARRIS Touchstone cable modem. This vulnerability indicates a known device type, which can be used for reconnaissance and targeted attacks. Cable modems are often overlooked in security assessments but represent an entry point into home networks. A successful attack could lead to data theft, network compromise, or denial of service.
2. Technical Explanation
The remote host is identified as an ARRIS Touchstone cable modem. This does not indicate a specific technical flaw but rather the presence of a device with known characteristics. Attackers may use this information to identify vulnerable devices and attempt further exploitation, such as exploiting default credentials or firmware vulnerabilities. There are no known active exploits specifically targeting the identification of ARRIS Touchstone cable modems themselves; however, knowing the model allows for targeted attacks against known weaknesses in that specific hardware/firmware revision.
- Root cause: The device is an ARRIS Touchstone cable modem.
- Exploit mechanism: Attackers can use this information to target the device with exploits based on its model and firmware version.
- Scope: All ARRIS Touchstone cable modems are potentially affected.
3. Detection and Assessment
To confirm whether a system is an ARRIS Touchstone cable modem, you can use network scanning tools or check the device’s web interface. A quick check involves identifying the manufacturer string in the device’s information. Thorough methods include examining the HTTP headers returned by the device.
- Quick checks: Access the device’s web interface (usually 192.168.100.1) and look for “ARRIS Touchstone” in the model or manufacturer field.
- Scanning: Nmap can identify the device type using the following command:
nmap -p 80,443Look for ARRIS in the output. This is an example only. - Logs and evidence: Examine network traffic for HTTP headers containing “ARRIS Touchstone”.
nmap -p 80,443 4. Solution / Remediation Steps
The primary remediation step is to ensure the cable modem’s firmware is up-to-date and default credentials have been changed. Regular security audits should be performed on all network devices.
4.1 Preparation
- Backups are not typically available for cable modems, but record current configuration settings if possible. No services need to be stopped. A roll back plan involves restoring the device to factory defaults and reconfiguring it.
- Ensure you have access to the cable modem’s web interface and internet connectivity to download firmware updates. Change windows may be needed for service interruption during a reboot.
4.2 Implementation
- Step 1: Access the cable modem’s web interface (usually 192.168.100.1).
- Step 2: Log in with administrator credentials. Change default password if not already done.
- Step 3: Check for firmware updates under the “Administration” or “Firmware Upgrade” section.
- Step 4: Download and install any available firmware updates.
4.3 Config or Code Example
Before
Default Username: admin
Default Password: passwordAfter
Username:
Password: 4.4 Security Practices Relevant to This Vulnerability
Practices relevant to this vulnerability include regularly updating firmware and changing default credentials. Least privilege is also important, although less applicable directly to cable modems. Input validation can prevent attacks targeting the web interface.
- Practice 1: Patch cadence – Regularly update firmware to address known vulnerabilities.
4.5 Automation (Optional)
Automation is not typically available for cable modems due to limited configuration options and lack of API access.
5. Verification / Validation
- Post-fix check: Access the cable modem’s web interface and verify the updated firmware version is displayed.
- Re-test: Re-run the quick check from Section 3, confirming that the device still identifies as an ARRIS Touchstone model with the new firmware version.
- Smoke test: Browse to a known website (e.g., google.com) to confirm internet connectivity is working.
- Monitoring: Monitor network logs for any unusual activity originating from the cable modem’s IP address. This is an example only.
Firmware Version: 6. Preventive Measures and Monitoring
Preventive measures include updating security baselines to require firmware updates and strong passwords on all network devices. Regularly review device configurations for any deviations from the baseline. For example, implement a policy requiring monthly firmware checks.
- Baselines: Update your security baseline or policy to mandate regular firmware updates on cable modems.
- Pipelines: Consider using network scanning tools in CI/CD pipelines to identify outdated devices.
- Asset and patch process: Implement a monthly review cycle for all network device configurations and firmware versions.
7. Risks, Side Effects, and Roll Back
Risks include potential service interruption during the firmware update process or incompatibility with certain ISP services. A roll back involves restoring the device to factory defaults and reconfiguring it manually.
- Risk or side effect 1: Firmware updates can sometimes cause temporary service outages.
- Risk or side effect 2: In rare cases, a firmware update may render the device unusable.
- Roll back: 1) Reset the cable modem to factory defaults using the reset button. 2) Reconfigure the device with your ISP settings. 3) Verify internet connectivity.
8. References and Resources
Links only to sources that match this exact vulnerability. Use official advisories and trusted documentation. Do not include generic links.
- Vendor advisory or bulletin: http://www.arrisi.com/products/product.asp?id=50