How to remediate – Xerox Printer SNMP Detection

1. Introduction

The Xerox Printer SNMP Detection vulnerability means information about a Xerox printer can be obtained using the Simple Network Management Protocol. This allows attackers to gather details about your printers, potentially aiding in further attacks on your network. Affected systems are typically Xerox printers with SNMP enabled. A successful exploit could lead to information disclosure impacting confidentiality.

2. Technical Explanation

Xerox printers often have SNMP enabled by default. This allows remote querying of printer details like model and firmware version. An attacker can use standard SNMP tools to request this information without authentication if the community string is known or guessable. There is no specific CVE associated with this general detection, but it represents a common misconfiguration. For example, an attacker could discover the printer’s model number and firmware version to identify potential vulnerabilities in that specific device.

• Root cause: SNMP service enabled with default community strings or weak configuration.
• Exploit mechanism: An attacker sends SNMP queries to the printer using a known or guessed community string. Tools like snmpwalk are commonly used. Example payload: snmpwalk -v2c -c public 192.168.1.100 .1.3.6.1.2.1.1
• Scope: Xerox printers with SNMP enabled, across various models and firmware versions.

3. Detection and Assessment

You can confirm if your system is vulnerable by checking if SNMP is enabled and accessible. A quick check involves attempting to retrieve printer information using a basic SNMP query. For thorough assessment, use a network scanner.

• Quick checks: Use the snmpwalk command to attempt to retrieve system information from the printer’s IP address.
• Scanning: Nessus plugin ID 10423 (Xerox Printer SNMP Information Disclosure) can identify this issue, as an example only.
• Logs and evidence: Check firewall logs for SNMP traffic originating from or destined to your printers. Look for connections on UDP port 161.

snmpwalk -v2c -c public 192.168.1.100 .1.3.6.1.2.1.1

4. Solution / Remediation Steps

The following steps detail how to disable or secure SNMP on your Xerox printer.

4.1 Preparation

• Ensure you have access credentials for the printer’s web interface. A roll back plan involves restoring the backed-up configuration.
• A change window may be needed to minimise disruption. Approval from the IT security team might be necessary.

4.2 Implementation

1. Step 1: Log in to the printer’s web interface using a browser.
2. Step 2: Navigate to the SNMP configuration settings (usually under Network or Security).
3. Step 3: Disable the SNMP service if possible.
4. Step 4: If disabling is not an option, change the default community string to a strong, unique value.
5. Step 5: Restrict access to SNMP by configuring allowed IP addresses in the printer’s firewall settings.

4.3 Config or Code Example

Before

Community String: public

After

Community String: StrongUniqueString123!

4.4 Security Practices Relevant to This Vulnerability

Several security practices can help prevent this issue.

• Practice 1: Least privilege – only enable services that are absolutely necessary and restrict access as much as possible.

4.5 Automation (Optional)

Automation is difficult without specific printer management tools, so this section is not applicable in most cases.

5. Verification / Validation

• Post-fix check: Run snmpwalk -v2c -c StrongUniqueString123! 192.168.1.100 .1.3.6.1.2.1.1 (replace with your new community string). You should receive a “No Such Name” error or timeout.
• Re-test: Re-run the initial snmpwalk command using the default community string (“public”). It should no longer return printer information.
• Monitoring: Monitor firewall logs for any unexpected SNMP traffic to or from your printers, as an example only.

snmpwalk -v2c -c StrongUniqueString123! 192.168.1.100 .1.3.6.1.2.1.1

6. Preventive Measures and Monitoring

Update security baselines to include SNMP hardening guidelines for example.

• Baselines: Update your printer security baseline or policy to require disabling SNMP or using strong community strings. Consider CIS controls related to network services.
• Pipelines: Implement configuration management tools to enforce the desired SNMP settings across all printers.
• Asset and patch process: Include regular reviews of printer configurations as part of your asset management process. A quarterly review cycle is sensible.

7. Risks, Side Effects, and Roll Back

Disabling SNMP may affect network monitoring tools that rely on it.

• Risk or side effect 1: Disabling SNMP could break existing network management systems. Mitigation involves updating those systems to use alternative protocols.
• Roll back: Restore the backed-up printer configuration if any issues occur. Re-enable SNMP with the original settings if necessary.

8. References and Resources

Links only to sources that match this exact vulnerability.

• Vendor advisory or bulletin: Check the Xerox support website for specific security advisories related to SNMP on your printer model.
• NVD or CVE entry: No specific CVE exists for this general detection, but search NVD for vulnerabilities affecting Xerox printers and SNMP.
• Product or platform documentation relevant to the fix: Refer to the Xerox printer’s user manual for instructions on configuring SNMP settings.