CVE-2024-33610 is a critical authentication bypass vulnerability discovered in multiple Sharp Corporation multifunction printers (MFPs). The flaw arises because two web interface endpoints, 'sessionlist.html' and 'sys_trayentryreboot.html', are accessible without any authentication. The 'sessionlist.html' page exposes session information of logged-in users, including session cookies, which can be leveraged by attackers to hijack active sessions and gain unauthorized access to the device's management interface. The 'sys_trayentryreboot.html' endpoint allows an attacker to reboot the device remotely without authentication, potentially causing denial of service or disruption of printing services. The vulnerability is exploitable remotely over the network without any user interaction or privileges, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The impact on confidentiality and integrity is high, as attackers can both access sensitive session data and control device operations. Although no public exploits have been reported yet, the ease of exploitation and critical nature of the flaw necessitate urgent attention. The affected product versions have not been explicitly listed here but are detailed by Sharp Corporation in their advisories. This vulnerability highlights the risks of insufficient access controls on embedded web interfaces in networked devices like MFPs, which are often overlooked in enterprise security.

For European organizations, this vulnerability presents a significant risk to the confidentiality and integrity of sensitive information processed or stored on Sharp MFP devices. Attackers exploiting this flaw can hijack active sessions to gain unauthorized administrative access, potentially leading to data leakage, manipulation of print jobs, or configuration changes. The ability to reboot devices without authentication can disrupt business operations, causing denial of service and impacting productivity. Organizations in sectors such as government, finance, healthcare, and critical infrastructure that rely heavily on multifunction printers for document handling are particularly vulnerable. The exposure of session cookies can also facilitate lateral movement within internal networks if attackers gain footholds. Given the network-exploitable nature and lack of required privileges or user interaction, the threat surface is broad, especially in environments where MFPs are accessible from less secure network segments or exposed to the internet. This vulnerability could also undermine compliance with data protection regulations like GDPR if sensitive data is compromised.

1. Immediately consult Sharp Corporation’s official security advisories to identify affected models and apply vendor-provided patches or firmware updates as soon as they become available. 2. Until patches are deployed, restrict network access to Sharp MFP web interfaces by implementing network segmentation and firewall rules that limit access to trusted management networks only. 3. Disable or restrict access to the vulnerable web endpoints ('sessionlist.html' and 'sys_trayentryreboot.html') if possible through device configuration or web server controls. 4. Monitor network traffic and device logs for unusual access patterns or repeated requests to these endpoints, which may indicate exploitation attempts. 5. Enforce strong authentication and session management policies on MFPs, including session timeouts and use of secure cookies, to minimize session hijacking risks. 6. Conduct regular security assessments of networked printing devices and include them in vulnerability management programs. 7. Educate IT and security teams about the risks of embedded device web interfaces and the importance of timely patching and access controls. 8. Consider isolating MFPs on dedicated VLANs with strict ingress and egress filtering to reduce exposure.