Microsoft Windows 11 24H2/Server 2022 23H2/Server 2025 NTLM V1 incorrect implementation of authentication algorithm

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 (≈)
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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.
8.9$5k-$25k0.00

Summaryinfo

A vulnerability labeled as very critical has been found in Microsoft Windows 11 24H2/Server 2022 23H2/Server 2025. This vulnerability affects unknown code of the component NTLM V1. The manipulation results in incorrect implementation of authentication algorithm. This vulnerability is identified as CVE-2025-21311. The attack can be executed remotely. There is not any exploit available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Microsoft Windows 11 24H2/Server 2022 23H2/Server 2025. Affected is an unknown part of the component NTLM V1. The manipulation with an unknown input leads to a incorrect implementation of authentication algorithm vulnerability. CWE is classifying the issue as CWE-303. The requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect. This is going to have an impact on confidentiality, integrity, and availability.

The weakness was released 01/14/2025 as confirmed security update guide (Website). The advisory is shared for download at msrc.microsoft.com. This vulnerability is traded as CVE-2025-21311. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 01/25/2025).

The vulnerability scanner Nessus provides a plugin with the ID 214136 (KB5049984: Windows 11 version 22H2 / Windows Server version 23H2 Security Update (January 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 (214136). Once again VulDB remains the best source for vulnerability data.

Productinfo

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Vendor

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Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 8.9

VulDB Base Score: 9.8
VulDB Temp Score: 8.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 9.8
Vendor Vector (Microsoft): 🔍

CNA Base Score: 9.8
CNA Vector (Microsoft): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Incorrect implementation of authentication algorithm
CWE: CWE-303
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Unproven

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 214136
Nessus Name: KB5049984: Windows 11 version 22H2 / Windows Server version 23H2 Security Update (January 2025)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

01/14/2025 🔍
01/14/2025 +0 days 🔍
01/14/2025 +0 days 🔍
01/25/2025 +11 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2025-21311 (🔍)
GCVE (CVE): GCVE-0-2025-21311
GCVE (VulDB): GCVE-100-291756

Entryinfo

Created: 01/14/2025 20:00
Updated: 01/25/2025 10:27
Changes: 01/14/2025 20:00 (35), 01/14/2025 20:04 (34), 01/15/2025 02:03 (2), 01/25/2025 10:27 (10)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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