1. Introduction
The AT&T U-verse Arris Modems NVG589 / NVG599 / 5268AC are affected by multiple vulnerabilities, including remote code execution flaws. This impacts the confidentiality, integrity and availability of networks using these devices. These modems are commonly found in residential internet setups provided by AT&T U-verse. A successful exploit could allow an attacker to take control of the modem and potentially compromise the entire network it serves.
2. Technical Explanation
The Arris device self-reports as model NVG589, NVG599 or 5268AC, triggering detection of multiple vulnerabilities including a firewall bypass, hardcoded credentials, privilege escalation and remote code execution. Nessus detects this based on the reported model number, not firmware version. An attacker could exploit these flaws to gain unauthorized access and control of affected devices.
- Root cause: Multiple issues exist within the Arris device’s software including default or hardcoded credentials, flawed firewall rules, and insecure privilege handling.
- Exploit mechanism: Attackers can leverage remote code execution vulnerabilities to execute arbitrary commands on the modem. This may involve sending specially crafted network packets or exploiting web interface flaws.
- Scope: Affected devices are Arris NVG589, NVG599 and 5268AC modems. The specific firmware versions affected have not been fully determined by Nessus at this time.
3. Detection and Assessment
Confirming vulnerability requires checking the device model number. A thorough assessment involves reviewing logs for suspicious activity.
- Quick checks: Access the modem’s web interface (typically 192.168.1.1) and check the ‘Device Info’ or similar section to confirm the model number is NVG589, NVG599 or 5268AC.
- Scanning: Nessus vulnerability scan with plugin ID(s) related to Arris modem vulnerabilities can identify affected devices.
- Logs and evidence: Review modem logs for unusual activity, failed login attempts, or unexpected commands being executed. Specific log file locations vary by firmware version.
# Example command placeholder:
# No direct command available without access to the device's CLI. Check web interface as described above.
4. Solution / Remediation Steps
Currently, no vendor-supplied fix is available for these vulnerabilities. Contacting AT&T U-verse support is the recommended course of action.
4.1 Preparation
- Backups: No specific backups are required at this time as a direct fix isn’t possible without firmware updates.
- Dependencies: None.
- Roll back plan: As no changes are being made, there is no roll back procedure needed.
- Change window needs: Contact AT&T U-verse support during normal business hours for assistance.
4.2 Implementation
- Step 1: Contact AT&T U-verse support and report the vulnerability. Request information on available firmware updates or replacement options.
4.3 Config or Code Example
No configuration changes are possible at this time as a direct fix isn’t available.
Before
N/A - No config change possible without firmware updateAfter
N/A - Firmware update required from vendor.4.4 Security Practices Relevant to This Vulnerability
While a direct fix is not available, maintaining a strong security posture can reduce risk.
- Practice 1: Network segmentation can limit the impact of a compromised modem on other devices within the network.
- Practice 2: Regularly review firewall rules to ensure only necessary ports and services are exposed.
4.5 Automation (Optional)
No automation is possible at this time without firmware updates.
N/A - No automated fix available.5. Verification / Validation
Verification involves confirming the modem has been updated with a security patch or replaced with a secure model.
- Post-fix check: Access the modem’s web interface and verify the firmware version is updated to a version that addresses these vulnerabilities (information from AT&T U-verse support).
- Re-test: Re-run Nessus vulnerability scan to confirm the vulnerability is no longer detected.
- Monitoring: Monitor modem logs for unusual activity, failed login attempts, or unexpected commands being executed (example log query: search for authentication failures).
# Example command placeholder:
# No direct command available without access to the device's CLI. Check web interface as described above.
6. Preventive Measures and Monitoring
Preventive measures focus on proactive security practices.
- Baselines: Implement a security baseline for all network devices, including modems, to ensure consistent configuration settings.
- Asset and patch process: Establish a regular patch management cycle for all network devices, including modems.
7. Risks, Side Effects, and Roll Back
The primary risk is continued exposure until a fix is applied. There are no known side effects from contacting AT&T U-verse support.
- Risk or side effect 1: Continued vulnerability until a patch is available.
- Roll back: N/A – No changes were made to the device, so there is nothing to roll back.
8. References and Resources
Links to relevant resources for this specific vulnerability.
- Vendor advisory or bulletin: https://www.nomotion.net/blog/sharknatto/
- NVD or CVE entry: CVE-2017-10793, CVE-2017-14115, CVE-2017-14116, CVE-2017-14117
- Product or platform documentation relevant to the fix: N/A – No direct documentation available without firmware updates.