CVE-2002-1796 in ChaiVM
Summary
by MITRE
ChaiVM EZloader for HP color LaserJet 4500 and 4550 and HP LaserJet 4100 and 8150 does not properly verify JAR signatures for new services, which allows local users to load unauthorized Chai services.
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Analysis
by VulDB Data Team • 01/16/2025
The vulnerability identified as CVE-2002-1796 affects ChaiVM EZloader implementations on several HP LaserJet printer models including the 4500, 4550, 4100, and 8150 series. This represents a critical security flaw in the printer firmware's Java-based service execution environment where proper signature verification mechanisms have been bypassed. The vulnerability specifically targets the verification process for JAR (Java Archive) files that contain new services to be loaded by the printer's ChaiVM runtime environment.
The technical flaw stems from inadequate cryptographic signature validation within the printer's service loading mechanism. When the EZloader attempts to load new Chai services, it fails to properly validate the digital signatures associated with JAR files containing these services. This weakness allows malicious actors with local access to the printer to craft or modify JAR files that appear legitimate to the system while actually containing unauthorized code. The vulnerability is classified under CWE-327, which addresses broken cryptographic algorithms and improper implementation of cryptographic protocols. The lack of signature verification creates an environment where arbitrary code execution becomes possible through service manipulation.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on HP LaserJet printers in their network infrastructure. Local attackers who gain physical access to the printer or can establish a network presence that allows them to interact with the printer's service loading mechanisms can exploit this flaw to execute unauthorized code. The impact extends beyond simple code execution as it could potentially allow attackers to modify printer behavior, access sensitive print jobs, or use the compromised printer as a pivot point for further network attacks. This vulnerability aligns with ATT&CK technique T1059.007 for Windows Command and Scripting Interpreter, though adapted to printer environments where Java-based services are executed.
The mitigation strategies for this vulnerability involve implementing proper signature verification mechanisms within the printer firmware, ensuring that all JAR files are validated before service execution, and restricting local access to printer management interfaces. Organizations should also consider network segmentation to limit access to printer services and implement monitoring for unusual service loading activities. Additionally, regular firmware updates from HP should be applied to address the underlying signature verification issues, as this vulnerability represents a fundamental flaw in the cryptographic implementation of the printer's service loading system. The remediation process requires both immediate firmware patching and long-term security architecture improvements to prevent similar signature verification failures in printer-based Java runtime environments.