CVE-1999-1062 is a high-severity vulnerability affecting HP LaserJet printers equipped with JetDirect network interface cards when configured to use TCP/IP. The vulnerability allows remote attackers to bypass print filters by directly sending PostScript documents to the printer's TCP ports 9099 and 9100. Normally, print filters are used to control or sanitize print jobs, preventing unauthorized or malicious content from being printed. However, due to this flaw, an attacker can circumvent these controls by communicating directly with the printer's network interface, submitting arbitrary PostScript code. This can lead to unauthorized printing, potential information disclosure, or disruption of printing services. The vulnerability has a CVSS v2 score of 7.5, indicating high severity, with network attack vector (AV:N), low attack complexity (AC:L), no authentication required (Au:N), and impacts on confidentiality, integrity, and availability (C:P/I:P/A:P). Although this vulnerability was published in 1997 and no patches are available, it remains relevant in environments where legacy HP LaserJet printers with JetDirect cards are still in use. Exploitation does not require user interaction and can be performed remotely over the network, making it a significant risk in exposed network environments.

For European organizations, this vulnerability poses several risks. Unauthorized remote printing can lead to leakage of sensitive documents if attackers can intercept or manipulate print jobs. The ability to bypass print filters means malicious or inappropriate content could be printed, potentially causing reputational damage or operational disruption. Additionally, attackers could exploit this to launch denial-of-service attacks against printing infrastructure by flooding the printer with malicious PostScript commands, impacting business continuity. Organizations relying on legacy HP LaserJet printers connected to corporate networks without adequate segmentation or firewall rules are particularly vulnerable. Given the critical role of printing in many administrative and operational processes, disruption or compromise of printing services can affect productivity and information security compliance, especially under strict European data protection regulations such as GDPR.

Since no official patches are available for this vulnerability, European organizations should implement compensating controls. First, network segmentation should isolate printers from general user networks, restricting access to trusted hosts only. Firewall rules should explicitly block inbound traffic to TCP ports 9099 and 9100 from untrusted sources. Where possible, disable unused network printing protocols or services on the JetDirect cards. Organizations should consider replacing legacy HP LaserJet printers with modern devices that have updated firmware and security features. Monitoring network traffic for unusual activity targeting printer ports can help detect exploitation attempts. Additionally, implementing strict print job authentication and logging can provide audit trails to identify unauthorized printing. Finally, educating IT staff about legacy device risks and maintaining an asset inventory to identify vulnerable printers is essential for proactive risk management.