CVE-2019-6489 in Lexmark
Summary
by MITRE
Certain Lexmark CX, MX, X, XC, XM, XS, and 6500e devices before 2019-02-11 allow remote attackers to erase stored shortcuts.
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Analysis
by VulDB Data Team • 05/09/2020
The vulnerability identified as CVE-2019-6489 affects a range of Lexmark multifunction devices including CX, MX, X, XC, XM, XS series and the 6500e model. These devices are widely deployed in enterprise environments for document management and printing services, making them critical components of organizational infrastructure. The flaw resides in the device's web-based management interface which fails to properly validate user authentication and authorization before allowing modification of stored shortcuts. This vulnerability represents a significant security weakness that could be exploited by remote attackers without requiring any local access or credentials. The affected devices operate with web server functionality that exposes administrative interfaces accessible over network connections, creating potential attack vectors for malicious actors positioned outside the network perimeter.
The technical implementation of this vulnerability stems from insufficient input validation and access control mechanisms within the device's configuration management system. When users attempt to modify stored shortcuts through the web interface, the system does not adequately verify whether the requesting entity possesses proper authorization to perform such operations. This authentication bypass allows attackers to manipulate shortcut configurations remotely, potentially disrupting legitimate business operations or creating opportunities for further exploitation. The flaw specifically impacts the device's ability to maintain secure access controls for administrative functions, enabling unauthorized modification of system settings that control device behavior and network connectivity. This issue is classified under CWE-285, which addresses improper authorization in software systems, and aligns with ATT&CK technique T1068, which involves exploiting local system permissions to gain unauthorized access.
The operational impact of CVE-2019-6489 extends beyond simple configuration modification as it can lead to significant business disruption and potential data exposure. Attackers who successfully exploit this vulnerability can erase critical shortcuts that may contain network configuration details, printer settings, or device management parameters essential for normal operations. This capability allows malicious actors to disrupt document workflows, potentially causing delays in business processes or creating situations where devices become unusable until manual reconfiguration occurs. The remote nature of the attack means that threat actors can target these devices from anywhere on the internet, increasing the attack surface and reducing the effectiveness of traditional network security controls. Organizations may experience unauthorized modification of device settings that could affect print job routing, network security policies, or integration with enterprise document management systems. The vulnerability also creates opportunities for attackers to establish persistent access points within the network, as modified shortcuts might redirect traffic or provide alternative access methods.
Mitigation strategies for CVE-2019-6489 should focus on immediate firmware updates provided by Lexmark to address the authentication bypass vulnerability. Organizations must ensure all affected devices receive the latest security patches before the specified date of 2019-02-11, as this represents the deadline for the vendor's official fix. Network segmentation and firewall rules should be implemented to restrict access to device management interfaces, limiting exposure to trusted network segments only. Additionally, administrators should disable unnecessary web services and ensure that only authorized personnel have access to administrative functions through strong authentication mechanisms. Regular monitoring of device logs for unauthorized configuration changes and implementing network intrusion detection systems can help identify potential exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date device firmware and implementing robust access control policies for networked printing infrastructure, as these devices often serve as entry points for broader network attacks. Organizations should also consider implementing network access control lists that restrict remote access to device management interfaces and establish procedures for regularly reviewing and validating device configurations to detect unauthorized modifications.