CVE-2019-18629 in AltaLink B8045
Summary
by MITRE • 03/04/2021
Xerox AltaLink B8045/B8055/B8065/B8075/B8090 and C8030/C8035/C8045/C8055/C8070 multifunction printers with software releases before 101.00x.099.28200 allow an attacker to execute an unwanted binary during a exploited clone install. This requires creating a clone file and signing that file with a compromised private key.
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Analysis
by VulDB Data Team • 03/14/2021
The vulnerability CVE-2019-18629 represents a critical security flaw in Xerox multifunction printers including models AltaLink B8045/B8055/B8065/B8075/B8090 and C8030/C8035/C8045/C8055/C8070. This issue stems from insufficient validation mechanisms during the clone installation process, creating an attack vector that allows remote code execution through malicious binary deployment. The vulnerability specifically affects firmware versions prior to 101.00x.099.28200, indicating a widespread impact across multiple printer models within the Xerox product line. The flaw operates through a sophisticated attack chain that requires an attacker to first compromise a private key used for digital signatures, then create a malicious clone file that can bypass the printer's security checks during installation.
The technical implementation of this vulnerability involves the exploitation of trust relationships within the printer's firmware update and clone installation mechanisms. When a printer processes a clone file during installation, it validates the digital signature to ensure authenticity and integrity of the software being installed. However, the flaw allows attackers to bypass this validation when they possess a compromised private key that can be used to sign malicious clone files. This creates a scenario where an attacker can inject arbitrary code into the printer's operating system, potentially gaining full administrative control over the device. The vulnerability aligns with CWE-310, which addresses cryptographic weaknesses in digital signature validation processes, and represents a significant deviation from secure coding practices that should enforce strict validation of all software components.
Operationally, this vulnerability presents severe implications for enterprise environments where multifunction printers serve as critical components of network infrastructure. Attackers could leverage this flaw to establish persistent backdoors on networked printers, potentially using them as entry points for lateral movement within corporate networks. The compromised printers could serve as staging points for further attacks, including data exfiltration, man-in-the-middle attacks on print jobs, or as pivot points for accessing other network resources. Additionally, the vulnerability could enable attackers to modify printer configurations, disable security features, or redirect print jobs to unauthorized destinations, creating both security and compliance risks for organizations. The attack requires relatively sophisticated capabilities to compromise a private key, but once achieved, provides attackers with a persistent foothold that can remain undetected for extended periods.
Organizations should implement immediate mitigations including prompt firmware updates to versions 101.00x.099.28200 or later, which address the validation weaknesses in the clone installation process. Network segmentation should be enforced to limit access to printer management interfaces, and strict access controls should be implemented for printer administration functions. Regular monitoring of printer network traffic and system logs can help detect anomalous behavior that might indicate exploitation attempts. Security teams should also consider implementing certificate pinning mechanisms and regularly auditing digital certificates used for printer authentication. The vulnerability demonstrates the importance of maintaining secure key management practices and implementing defense-in-depth strategies that protect not only primary systems but also peripheral devices that often serve as overlooked attack vectors in enterprise security architectures. Organizations should also review their supply chain security practices and ensure proper verification of all firmware updates before deployment to prevent similar vulnerabilities from being introduced through compromised update processes.