CVE-2024-38104 is a remote code execution vulnerability identified in the Windows Fax Service component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The root cause is an untrusted pointer dereference (CWE-822), which occurs when the Fax Service improperly handles pointers from untrusted sources. This flaw allows an attacker with low privileges (PR:L) to remotely execute arbitrary code on the vulnerable system without requiring user interaction (UI:N). The attack vector is network-based (AV:N), meaning an attacker can exploit this vulnerability remotely over the network. The vulnerability affects the confidentiality, integrity, and availability of the system, as arbitrary code execution can lead to full system compromise. The CVSS v3.1 base score is 8.8, reflecting high severity with low attack complexity (AC:L) and no user interaction needed. Although no known exploits are currently reported in the wild, the vulnerability is critical for environments still running Windows 10 Version 1809, which is out of mainstream support and may not receive timely patches. The Fax Service is often enabled in enterprise environments that rely on legacy fax communications, increasing the attack surface. The vulnerability’s exploitation could allow attackers to deploy malware, steal sensitive information, or disrupt services. Given the lack of a patch link, organizations must prioritize mitigation through alternative means such as disabling the Fax Service or upgrading the OS.

For European organizations, the impact of CVE-2024-38104 is significant, especially for those still operating Windows 10 Version 1809 in production environments. The vulnerability enables remote attackers to gain full control over affected systems, potentially leading to data breaches, ransomware deployment, or disruption of critical services. Sectors such as healthcare, government, finance, and manufacturing that may still use fax services for regulatory or operational reasons are particularly at risk. The compromise of systems could lead to loss of sensitive personal data protected under GDPR, resulting in legal and financial penalties. Additionally, disruption of fax-dependent workflows could impact business continuity. The vulnerability’s network-based attack vector and lack of user interaction requirement increase the likelihood of automated exploitation attempts once a public exploit emerges. The absence of known exploits currently provides a window for proactive defense, but the risk remains high due to the severity and potential impact on confidentiality, integrity, and availability.

1. Upgrade affected systems from Windows 10 Version 1809 to a supported and patched Windows version (e.g., Windows 10 21H2 or later, or Windows 11) to receive security updates and eliminate the vulnerability. 2. If upgrading is not immediately feasible, disable the Windows Fax Service on all affected systems to remove the attack surface. This can be done via Services management console or PowerShell commands. 3. Implement network-level controls such as firewall rules to restrict access to the Fax Service ports (typically TCP 455) from untrusted networks. 4. Monitor network traffic and system logs for unusual activity related to the Fax Service or unexpected remote code execution attempts. 5. Apply strict privilege management to limit the ability of low-privilege users to interact with the Fax Service. 6. Conduct vulnerability scanning and asset inventory to identify all systems running Windows 10 Version 1809 and prioritize remediation. 7. Educate IT staff about this vulnerability and ensure incident response plans include steps for potential exploitation scenarios. 8. Stay updated with Microsoft advisories for any forthcoming patches or mitigations.