Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability

Technical Severity

CVSS v3.1 Metrics

HIGH

7.8 / 10

Minimal Risk Critical

Vector Specification

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

Exploitation Likelihood

EPSS Prediction

13.58 %

Predictive Probability

Percentile Rank

94.2 th

Documented as more likely to be exploited than 94.2% of known CVEs.

Detection Date

Feb 11, 2025

Remediation Due

Mar 04, 2025

CISA Catalog Active

Threat Analysis

Microsoft Windows Ancillary Function Driver for WinSock contains a heap-based buffer overflow vulnerability that allows for privilege escalation, enabling a local attacker to gain SYSTEM privileges.

Remediation Directive

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

External Intelligence

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21418

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2025-21418