CVE-2024-47939 is a high-severity stack-based buffer overflow vulnerability affecting multiple laser printers and multifunction printers (MFPs) manufactured by Ricoh Company, Ltd. that implement the Ricoh Web Image Monitor feature. This vulnerability arises from improper handling of specially crafted requests sent to the Web Image Monitor interface, which is a web-based management tool for these devices. When exploited, the overflow can allow an attacker to execute arbitrary code on the affected device or cause a denial-of-service (DoS) condition by crashing the device. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, but it has a high attack complexity, meaning that crafting a working exploit requires significant effort or specific conditions. The CVSS v3.0 base score is 7.7, reflecting high impact on confidentiality and integrity, with a lower impact on availability. The affected versions are not explicitly listed in the provided information but are detailed by the vendor. No known exploits are currently reported in the wild. This vulnerability targets the embedded web server component of Ricoh printers and MFPs, which are commonly used in enterprise and organizational environments for document management and printing tasks. Exploitation could lead to full compromise of the device, enabling attackers to intercept print jobs, manipulate device settings, or use the device as a foothold for lateral movement within a network.

For European organizations, this vulnerability poses a significant risk due to the widespread use of Ricoh printers and MFPs in corporate, governmental, and educational institutions. Successful exploitation could lead to unauthorized access to sensitive documents, disruption of printing services, and potential network infiltration if the compromised device is used as a pivot point. Confidentiality is at high risk because print jobs often contain sensitive or confidential information. Integrity is also at risk since attackers could alter device configurations or print outputs. Availability impact is moderate but still relevant due to possible DoS conditions. The risk is heightened in environments where printers are exposed to untrusted networks or where network segmentation is insufficient. Given the remote exploitability without authentication, attackers could target these devices from outside the organization if the devices are accessible over the internet or poorly secured internal networks.

Organizations should immediately identify all Ricoh laser printers and MFPs implementing the Web Image Monitor feature within their networks. They should consult Ricoh's official security advisories and apply any available firmware updates or patches addressing CVE-2024-47939. If patches are not yet available, organizations should restrict network access to the Web Image Monitor interface by implementing network segmentation and firewall rules to limit access only to trusted management networks. Disabling the Web Image Monitor feature temporarily, if feasible, can reduce exposure. Monitoring network traffic for unusual requests targeting printer web interfaces can help detect exploitation attempts. Additionally, organizations should enforce strong network perimeter defenses, including VPNs or secure management channels for printer administration. Regularly auditing printer firmware versions and configurations will help maintain security posture. Finally, educating IT staff about this vulnerability and ensuring incident response plans include printer-related threats will enhance preparedness.