Xerox VersaLink Printer Vulnerabilities: A Threat to Your Windows Network

In an era where every device on your network is a potential entry point for attackers, the latest revelations surrounding Xerox VersaLink printer vulnerabilities serve as a stark reminder of the hidden risks. These vulnerabilities not only jeopardize the printers themselves but also pave the way for attackers to capture critical Windows Active Directory credentials—fueling lateral movement within enterprise networks.

The Mechanics of the Attack: Understanding Pass-Back Attacks​

At the heart of this issue lie pass-back attacks. In a typical pass-back attack scenario, the Xerox VersaLink printer is tricked into authenticating against a server controlled by the attacker. Here’s how it works:

• Modifying Service Configurations: An adversary with access to the printer’s configuration page can redirect authentication requests. For instance, if the printer uses the Lightweight Directory Access Protocol (LDAP) for authentication, the attacker simply changes the server's IP address to point to a malicious system.
• Credential Capture: Once the printer directs its authentication queries to the attacker’s server, clear text credentials for services like LDAP (or even SMB and FTP in some configurations) are sent directly to this rogue server.

This means that if someone manages to compromise a printer’s administrative settings, they may capture credentials that unlock not just the printer, but gateway systems across a Windows network.

How the Xerox Vulnerabilities Work​

The vulnerabilities—identified as CVE-2024-12510 and CVE-2024-12511—affect several Xerox VersaLink models, including the C7020, C7025, and C7030 series. The attack surfaces vary depending on the service configured on the printer:

• LDAP-Based Attacks: When LDAP services are active and misconfigured, an attacker can alter the IP address to point to a machine under their control. This redirection tricks the printer into sending its clear text authentication data to the malicious server.
• SMB/FTP Attacks: Conversely, if the printer’s user address book is set up to perform SMB or FTP scans, an attacker with remote access (or even physical proximity to the printer) can modify these settings. In doing so, they can capture:
• NetNTLMv2 handshakes, which are a critical component in Windows Active Directory authentication.
• Clear text FTP credentials, creating another vector for lateral movement.

The attacker thus not only gains access to the printer but also to Windows Active Directory credentials. With these credentials in hand, they can potentially move laterally within the network, targeting other Windows servers and file systems.

Implications for Windows Security Environments​

For network administrators and IT security teams focused on Windows environments, the implications are direct and concerning. An attacker who captures Windows authentication credentials via these printer vulnerabilities might:

• Bypass Network Segmentation: Once inside, they can leverage acquired privileges to traverse across segmented network zones—often bypassing conventional firewall safeguards.
• Compromise Critical Systems: With elevated access, lateral movement can lead to the compromise of critical file servers, databases, and other mission-critical Windows resources.
• Exploit Trust Relationships: Given the nature of Windows Active Directory, where trust relationships are paramount, an attacker might even leverage these credentials to facilitate further attacks—amplifying the potential damage.

This vulnerability underscores the need for robust defenses not only in servers and endpoints but across all network-connected devices—even those that seem peripheral, like printers.

Patching Up: What’s Being Done​

Xerox has responded to the issue by releasing security updates that patch these vulnerabilities. The fixes are bundled in service pack updates for the affected models and are rolled out as firmware version 57.75.53. Administrators are strongly advised to:

• Update Firmware Promptly: Ensure that all affected Xerox VersaLink printers are upgraded to firmware version 57.75.53 without delay.
• Review Configurations Regularly: Even with updated firmware, periodically auditing printer configurations can help catch any unauthorized changes that might expose your network.

Best Practices for Securing Network Printers and Windows Environments​

Given the potential havoc that these vulnerabilities could unleash, IT administrators should consider adopting the following best practices:

• Enforce Strong Administrative Credentials: Use complex, non-default passwords for printer admin accounts, reducing the risk of unauthorized configuration changes.
• Disable Unauthenticated Access: Restrict access to the printer’s remote-control console. If administrative access is required, ensure it is safeguarded with unique credentials.
• Limit Elevated Privileges: Avoid using Windows authentication accounts with elevated privileges on printer configurations. This limits the scope of what can be captured if a breach occurs.
• Network Segmentation: Place printers on a dedicated VLAN or subnet. This compartmentalization can prevent attackers from easily pivoting from a compromised printer to critical Windows servers.
• Regular Auditing and Monitoring: Incorporate printers into your regular security audits. Monitoring for unusual configuration changes can help detect and prevent potential attacks early.

Final Thoughts​

The Xerox VersaLink vulnerability is a clear reminder that network security extends far beyond firewalls and antivirus software. Every device—from printers to IoT gadgets—can become a stepping stone for attackers if not properly secured. For Windows administrators and users alike, this underscores the importance of staying proactive in applying patches, regularly reviewing device configurations, and following best practices to safeguard every point of entry in your network ecosystem.
By embracing a culture of security awareness and ensuring that every device is updated and correctly configured, organizations can mitigate these risks and forge a more resilient defense against evolving cyber threats.
Stay safe, stay updated, and don’t let the smallest vulnerabilities become the biggest threat to your Windows environment!

---

Source: SecurityWeek Xerox Versalink Printer Vulnerabilities Enable Lateral Movement