Cyber Resilience

CVE-2025-21176

Memory Safety in Microsoft .Net Framework 3.5 … 4.8.1

Published
14 January 2025
Modified
06 May 2025
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.023 82th percentile
Risk Priority 68 floored blend · peak EPSS

Summary

CVE-2025-21176 is a high-severity Buffer Over-read (CWE-126) vulnerability in Microsoft .Net Framework. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked in the top 18% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-21176 is a remote code execution vulnerability affecting .NET, .NET Framework, and Visual Studio. It carries a CVSS 3.1 base score of 8.8 and is associated with CWE-126 along with an NVD-CWE-noinfo entry, indicating a high-severity flaw that can be triggered over a network connection.

An unauthenticated attacker can exploit the issue by convincing a user to interact with malicious content, such as opening a specially crafted file or visiting a hostile web page. Successful exploitation grants the attacker full confidentiality, integrity, and availability impact on the affected system without requiring prior authentication or elevated privileges.

Microsoft's security update guide for CVE-2025-21176 and related vendor advisories provide official remediation details and patch availability for supported versions of the affected components.

The associated EPSS score remains low at 0.0194 with no material increase from its peak value, indicating limited observed exploitation interest to date.

EU & UK References

Vulnerability Data

.NET, .NET Framework, and Visual Studio Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-49088Same product: Microsoft Windows 10 1507
CVE-2024-38127Same product: Microsoft Windows 10 1507
CVE-2025-21277Same product: Microsoft Windows 10 1507
CVE-2025-26672Same product: Microsoft Windows 10 1507
CVE-2025-47971Same product: Microsoft Windows 10 1507
CVE-2025-47973Same product: Microsoft Windows 10 1507
CVE-2025-49659Same product: Microsoft Windows 10 1507
CVE-2024-30039Same product: Microsoft Windows 10 1507
CVE-2024-26176Same product: Microsoft Windows 10 1507
CVE-2025-49684Same product: Microsoft Windows 10 1507

Affected Assets

microsoft
.net
8.0.0, 9.0.0
microsoft
visual studio 2017
15.0 — 15.9.69
microsoft
.net framework
3.5, 4.6, 4.6.2, 4.7, 4.7.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, bounds checking tests) directly finds buffer over-read flaws.

Engineering principles such as memory-safe design and bounds-checked abstractions structurally stop introduction of out-of-bounds reads.

Process isolation limits the blast radius of an over-read to the compromised domain.

Input validation enforces length and index constraints that prevent many externally triggered over-reads.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly prevent introduction of buffer over-read weaknesses.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover buffer over-read flaws via scanning or review.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software removes known instances of buffer over-read bugs.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development can detect buffer over-reads before release.

prevents

Secure SDLC mandates input validation and bounds checking that can prevent buffer over-reads.

prevents

Application security requirements can specify buffer-size and bounds-checking rules.

prevents

Secure architecture principles include memory-safety and bounds-checking design choices.

prevents

Secure coding standards directly require bounds-checked buffer access, mitigating over-reads.

References