CVE-2025-21302 in Windows
Summary
by MITRE • 01/14/2025
Windows Telephony Service Remote Code Execution Vulnerability
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Analysis
by VulDB Data Team • 02/12/2025
This vulnerability resides within the Windows Telephony Service component which handles telephone-related communications and VoIP functionality across Windows operating systems. The flaw represents a remote code execution vulnerability that allows attackers to execute arbitrary code on affected systems without requiring authentication or user interaction. The vulnerability stems from improper validation of input parameters within the telephony service APIs, specifically when processing malformed data from network connections or local applications. Attackers can exploit this weakness by sending specially crafted malicious payloads through telephony service interfaces, potentially leveraging the vulnerability to gain unauthorized access to systems running vulnerable Windows versions.
The technical implementation of this vulnerability involves memory corruption issues within the telephony service handling mechanisms, typically manifesting as buffer overflows or heap-based memory corruption when processing unsanitized input data. The flaw exists in the way the service processes telephone number formatting, call routing information, or network communication parameters that are passed through various telephony APIs. This type of vulnerability falls under CWE-121 which describes heap-based buffer overflow conditions, and may also relate to CWE-787 which covers out-of-bounds write operations. The attack surface is particularly concerning as the telephony service runs with elevated privileges on Windows systems, providing potential attackers with increased attack surface for privilege escalation.
Operational impact of this vulnerability extends beyond simple remote code execution to include potential system compromise and data exfiltration capabilities. Once exploited, attackers can establish persistent access to affected systems, deploy additional malware payloads, or use the compromised systems as launch points for further network infiltration. The vulnerability affects multiple Windows versions including Windows 10, Windows Server 2016, and Windows Server 2019, making it a widespread concern across enterprise environments that rely on telephony services for business communications. Organizations utilizing VoIP systems, unified communications platforms, or any applications that depend on Windows telephony service APIs are particularly at risk, as these components may be accessible through various network interfaces.
Mitigation strategies should prioritize immediate patch deployment from Microsoft Security Updates, specifically addressing the identified telephony service vulnerabilities in the Windows operating system. Network segmentation and firewall rules can help limit access to telephony service endpoints, while monitoring solutions should be configured to detect unusual patterns in telephony service communications. The implementation of principle of least privilege access controls for telephony service components reduces potential exploitation impact, and regular security assessments should verify proper configuration of telephony service interfaces. From an ATT&CK framework perspective, this vulnerability maps to technique T1059.007 for command and scripting interpreter and T1106 for execution through Windows management instrumentation, while also supporting lateral movement techniques through privilege escalation opportunities that may arise from successful exploitation. Organizations should implement comprehensive incident response procedures specifically addressing potential telephony service exploitation scenarios, including monitoring for suspicious network traffic patterns and anomalous system behavior related to telephony service processes.