How to remediate – Xerox WorkCentre Multi-Page Document Scan/Fax Information Disc…

1. Introduction

The Xerox WorkCentre Multi-Page Document Scan/Fax Information Disclosure vulnerability affects remote printers. This issue allows a printer to potentially send faxes or scans to unintended recipients under specific, rare conditions. Businesses using these devices could experience confidential information being disclosed. The impact is likely low on confidentiality, integrity and availability.

2. Technical Explanation

This vulnerability occurs when faxing multi-page documents on a Xerox WorkCentre device. If a power failure happens during the second page scan and the user subsequently uses the fax or copy function more than 9,999 times, the printer may send the document to an incorrect addressee. The source of the alternate addressee is currently unknown.

• Root cause: The device does not reliably handle interrupted fax transmissions combined with high usage of fax/copy functions.
• Exploit mechanism: An attacker would need to trigger a power failure during the second page scan of a multi-page fax and then repeatedly use the fax or copy function over 9,999 times. This is unlikely but possible in environments with unstable power supplies and frequent printer usage.
• Scope: Xerox WorkCentre devices are affected. Specific models and software versions should be checked against version 1.02 to determine if they are vulnerable.

3. Detection and Assessment

Confirming vulnerability requires checking the device’s software version. A quick check can identify potentially affected units, while a thorough assessment involves monitoring fax transmissions under controlled conditions.

• Quick checks: Access the printer’s web interface and navigate to the “Information” or “Configuration” section to view the installed software version.
• Scanning: Nessus vulnerability scanner ID 12787 may detect this issue. This is an example only, other scanners might also report it.
• Logs and evidence: There are no specific logs that directly indicate this vulnerability. Monitoring fax transmission logs for unexpected recipients could provide indirect evidence.

# No command available to confirm exposure directly. Check the printer's web interface.

4. Solution / Remediation Steps

The solution is to update the Xerox WorkCentre device’s software to version 1.02 or later. Follow these steps for a safe and effective upgrade.

4.1 Preparation

• A change window may be needed depending on your organisation’s policies. Approval from an IT manager might also be required.

4.2 Implementation

1. Step 1: Download software version 1.02 from the Xerox Welcome Center.
2. Step 2: Access the printer’s web interface.
3. Step 3: Navigate to the “Firmware Update” or similar section.
4. Step 4: Upload the downloaded firmware file (version 1.02).
5. Step 5: Initiate the update process and allow the printer to restart automatically.

4.3 Config or Code Example

Before

# Software version prior to 1.02 (example: 1.01) - vulnerable configuration

After

# Software version 1.02 or later - updated and secure configuration

4.4 Security Practices Relevant to This Vulnerability

While this vulnerability is specific, general security practices can help reduce risk. Least privilege limits the impact of successful attacks. Patch cadence ensures timely updates for known issues.

• Practice 1: Implement least privilege access controls on printer configurations and network shares.
• Practice 2: Establish a regular patch management schedule to apply firmware updates promptly.

4.5 Automation (Optional)

No suitable automation script is available for this specific vulnerability due to the device-specific nature of the update process.

5. Verification / Validation

• Post-fix check: Access the printer’s web interface and confirm the installed software version is 1.02 or later.
• Re-test: Repeat the quick check to ensure the software version has been updated successfully.
• Smoke test: Send a simple multi-page fax to verify basic functionality remains intact.
• Monitoring: Monitor fax transmission logs for any unexpected recipient addresses as an early warning sign of potential issues. This is an example only, and may not be reliable.

# Check the printer's web interface for software version 1.02 or later.

6. Preventive Measures and Monitoring

Update security baselines to include the required firmware version. Consider adding checks in deployment pipelines to ensure printers are running supported versions. A sensible patch review cycle should be established based on risk assessment.

• Baselines: Update your printer security baseline to require software version 1.02 or later for all Xerox WorkCentre devices.
• Pipelines: Integrate firmware version checks into your deployment pipelines if possible.
• Asset and patch process: Review the firmware versions of printers regularly, at least quarterly, as part of your asset management process.

7. Risks, Side Effects, and Roll Back

Firmware updates can sometimes cause unexpected service disruptions or compatibility issues. A roll back plan is essential to restore previous functionality if needed.

• Risk or side effect 1: Firmware update may temporarily interrupt fax services.
• Risk or side effect 2: Compatibility issues with other printer features are possible, though unlikely.

8. References and Resources

• Vendor advisory or bulletin: http://www.nessus.org/u?f023617a
• NVD or CVE entry: No specific CVE is listed for this vulnerability.
• Product or platform documentation relevant to the fix: Refer to the Xerox WorkCentre device documentation for firmware update instructions.