VDB-315554 · CVE-2025-49735 · EUVD-2025-20620

Microsoft Windows Server 2012 up to Server 2022 23H2 KDC Proxy Service use after free

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.4	$25k-$100k	0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft Windows Server 2012 up to Server 2022 23H2. This affects an unknown function of the component KDC Proxy Service. Such manipulation leads to use after free. This vulnerability is traded as CVE-2025-49735. The attack may be launched remotely. There is no exploit available. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows Server 2012 up to Server 2022 23H2 and classified as critical. Affected by this issue is an unknown functionality of the component KDC Proxy Service. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Use after free in Windows KDC Proxy Service (KPSSVC) allows an unauthorized attacker to execute code over a network.

The weakness was shared 07/08/2025 as confirmed security update guide (Website). The advisory is available at msrc.microsoft.com. This vulnerability is handled as CVE-2025-49735. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $25k-$100k at the moment (estimation calculated on 02/13/2026).

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 EUVD (EUVD-2025-20620). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

Operating System

Vendor

Microsoft

Name

Windows

Version

License

commercial

Website

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

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.1
VulDB Meta Temp Score: 7.4

VulDB Base Score: 8.1
VulDB Temp Score: 7.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 8.1
Vendor Vector (Microsoft): 🔒

CNA Base Score: 8.1
CNA Vector (Microsoft): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Unproven

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔒
0-Day Time: 🔒
Exposure Time: 🔒

Timelineinfo

07/08/2025 VulDB entry created
07/08/2025 +0 days Advisory disclosed
07/08/2025 +0 days Countermeasure disclosed
02/13/2026 +220 days VulDB entry last update