Microsoft Windows up to Server 2025 Ancillary Function Driver for WinSock heap-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.5$5k-$25k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows. This issue affects some unknown processing of the component Ancillary Function Driver for WinSock. The manipulation results in heap-based overflow. This vulnerability is reported as CVE-2025-21418. The attack requires a local approach. Moreover, an exploit is present. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability was found in Microsoft Windows. It has been classified as critical. Affected is some unknown functionality of the component Ancillary Function Driver for WinSock. 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. CVE summarizes:

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

The weakness was disclosed 02/11/2025 as confirmed security update guide (Website). The advisory is shared for download at msrc.microsoft.com. This vulnerability is traded as CVE-2025-21418. The exploitability is told to be easy. The attack needs to be approached locally. Technical details are unknown but an exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 02/15/2025).

It is declared as attacked. This issue was added on 02/11/2025 to the CISA Known Exploited Vulnerabilities Catalog with a due date of 03/04/2025:

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

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 Zero-Day.cz (964). Once again VulDB remains the best source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.8
VulDB Meta Temp Score: 7.5

VulDB Base Score: 7.8
VulDB Temp Score: 7.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

Vendor Base Score (Microsoft): 7.8
Vendor Vector (Microsoft): 🔍

CNA Base Score: 7.8
CNA Vector (Microsoft): 🔍

CVSSv2info

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VulDB Base Score: 🔍
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VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Attacked

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EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍
KEV Notice: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

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

Timelineinfo

02/11/2025 🔍
02/11/2025 +0 days 🔍
02/11/2025 +0 days 🔍
02/15/2025 +4 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: msrc.microsoft.com
Status: Confirmed

CVE: CVE-2025-21418 (🔍)
GCVE (CVE): GCVE-0-2025-21418
GCVE (VulDB): GCVE-100-295332
scip Labs: https://www.scip.ch/en/?labs.20161215

Entryinfo

Created: 02/11/2025 19:38
Updated: 02/15/2025 20:48
Changes: 02/11/2025 19:38 (35), 02/11/2025 19:42 (34), 02/12/2025 04:25 (16), 02/12/2025 11:23 (12), 02/15/2025 20:48 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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