Microsoft Windows up to Server 2025 Telephony Service heap-based overflow

Summaryinfo

A vulnerability classified as critical has been found in Microsoft Windows. Affected by this issue is some unknown functionality of the component Telephony Service. Performing a manipulation results in heap-based overflow. This vulnerability is cataloged as CVE-2025-21407. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows. This affects some unknown processing of the component Telephony Service. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability.

The weakness was shared 02/11/2025 as confirmed security update guide (Website). The advisory is shared at msrc.microsoft.com. This vulnerability is uniquely identified as CVE-2025-21407. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $25k-$100k at the moment (estimation calculated on 02/15/2025).

The vulnerability scanner Nessus provides a plugin with the ID 216140 (KB5051979: Windows Server 2022 / Azure Stack HCI 22H2 Security Update (February 2025)), which helps to determine the existence of the flaw in a target environment.

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (216140). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Microsoft

Name

• Windows

Version

• 10
• 10 21H2
• 10 22H2
• 10 1607
• 10 1809
• 11 22H2
• 11 23H2
• 11 24H2
• Server 2008 R2 SP1
• Server 2008 SP2
• Server 2012
• Server 2012 R2
• Server 2016
• Server 2019
• Server 2022
• Server 2022 23H2
• Server 2025

License

• commercial

Website

• Vendor: https://www.microsoft.com/
• Product: https://www.microsoft.com/en-us/windows

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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