CVE-2024-38104 in Windows
Summary
by MITRE • 07/09/2024
Windows Fax Service Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 06/25/2026
The Windows Fax Service remote code execution vulnerability represents a critical security flaw that allows attackers to execute arbitrary code on affected systems without authentication. This vulnerability primarily affects Microsoft Windows operating systems where the fax service component is installed and enabled, making it particularly dangerous in enterprise environments where fax services are commonly deployed for document management and business communication purposes. The flaw stems from improper input validation within the fax service handling mechanisms that process incoming fax data and commands.
The technical implementation of this vulnerability involves a buffer overflow condition that occurs when the fax service processes malformed fax messages or specific command sequences sent over network connections. When an attacker sends specially crafted fax data to a vulnerable system, the service fails to properly validate the size and content of incoming data streams, leading to memory corruption that can be exploited to overwrite critical program execution pointers. This buffer overflow condition creates an opportunity for attackers to inject malicious code that executes with the privileges of the fax service account, typically running with elevated system permissions.
From an operational impact perspective, this vulnerability poses severe risks to organizations as it enables remote exploitation from any location without requiring user interaction or authentication credentials. Successful exploitation can result in complete system compromise, allowing attackers to establish persistent backdoors, escalate privileges to domain administrator levels, and access sensitive corporate data repositories. The vulnerability affects multiple Windows versions including server and desktop operating systems, with the highest risk exposure occurring on systems where fax services are actively configured and accessible over network interfaces. Network-based attacks can leverage this vulnerability to propagate laterally within corporate networks, potentially compromising multiple systems if proper network segmentation is not implemented.
Security professionals should implement immediate mitigations including disabling the fax service component on systems where it is not required, applying Microsoft security patches promptly, and configuring network access controls to restrict fax service communication to trusted sources only. The vulnerability aligns with CWE-121 stack-based buffer overflow conditions and maps to ATT&CK technique T1059.007 for remote code execution through service exploitation. Organizations should also consider implementing network monitoring solutions to detect unusual fax service activity and establish privileged access management controls to limit the impact of potential compromise. Regular security assessments and vulnerability scanning should include verification of fax service configurations to ensure that unnecessary services are disabled and that proper firewall rules are enforced to prevent unauthorized access to fax processing capabilities.