CVE-2025-27477: Windows Telephony Service Remote Code Execution Vulnerability

Overview

Severity

High (CVSS 8.8)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Category

Remote Code Execution

Exploit Status

Not Exploited

Exploitation Likelihood

Less Likely

Patch Tuesday

2025-Apr

Released

2025-04-08

Last Updated

2025-04-09

EPSS Score

3.51% (percentile: 87.6%)

Description

Heap-based buffer overflow in Windows Telephony Service allows an unauthorized attacker to execute code over a network.

FAQ

How could an attacker exploit this vulnerability? An attacker could exploit this vulnerability by tricking a user into sending a request to a malicious server. This could result in the server returning malicious data that might cause arbitrary code execution on the user's system. Are the updates for Windows 10 for x64-based Systems and Windows 10 for 32-bit Systems currently available? Yes. As of April 9, 2025, the security update (5055547) for Windows 10 for x64-based Systems and Windows 10 for 32-bit Systems are available. Customers running Windows 10 should ensure the update is installed to be protected from this vulnerability.

Affected Products (37)

Windows

• Windows 10 Version 1809 for 32-bit Systems
• Windows 10 Version 1809 for x64-based Systems
• Windows Server 2019
• Windows Server 2019 (Server Core installation)
• Windows Server 2022
• Windows Server 2022 (Server Core installation)
• Windows 10 Version 21H2 for 32-bit Systems
• Windows 10 Version 21H2 for ARM64-based Systems
• Windows 10 Version 21H2 for x64-based Systems
• Windows Server 2025 (Server Core installation)
• Windows 11 Version 23H2 for ARM64-based Systems
• Windows 11 Version 23H2 for x64-based Systems
• Windows Server 2022, 23H2 Edition (Server Core installation)
• Windows 11 Version 24H2 for ARM64-based Systems
• Windows 11 Version 24H2 for x64-based Systems
• Windows Server 2025
• Windows 10 for 32-bit Systems
• Windows 10 for x64-based Systems
• Windows 10 Version 1607 for 32-bit Systems
• Windows 10 Version 1607 for x64-based Systems
• Windows Server 2016
• Windows Server 2016 (Server Core installation)

ESU

• Windows 11 Version 22H2 for ARM64-based Systems
• Windows 11 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for x64-based Systems
• Windows 10 Version 22H2 for ARM64-based Systems
• Windows 10 Version 22H2 for 32-bit Systems
• Windows Server 2008 for 32-bit Systems Service Pack 2
• Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 for x64-based Systems Service Pack 2
• Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation)
• Windows Server 2008 R2 for x64-based Systems Service Pack 1
• Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
• Windows Server 2012
• Windows Server 2012 (Server Core installation)
• Windows Server 2012 R2
• Windows Server 2012 R2 (Server Core installation)

Security Updates (14)

• 5055519
• 5055526
• 5055518
• 5055528
• 5055523
• 5055527
• 5055547
• 5055521
• 5055609
• 5055596
• 5055561
• 5055570
• 5055581
• 5055557

Acknowledgments

Anonymous

Revision History

• 2025-04-08: Information published.
• 2025-04-09: The security updates for Windows 10 for 32-bit Systems and Windows 10 for x64-based Systems are now available. See the Security Updates table for more information.