Cyber Resilience

CVE-2025-21375

Memory Safety in Microsoft Windows Server 2008 r2

Published
11 February 2025
Modified
26 February 2025
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0064 47th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2025-21375 is a high-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 47th percentile by exploit likelihood (below the median); 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 SI-10 (Information Input Validation) — 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-2025-21375 is a Kernel Streaming WOW Thunk Service Driver Elevation of Privilege Vulnerability affecting Microsoft Windows operating systems. Published on 2025-02-11, the issue carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-20 (Improper Input Validation), CWE-122 (Heap-based Buffer Overflow), and NVD-CWE-noinfo.

The vulnerability can be exploited by a local attacker who already possesses low-level privileges on the target system. Exploitation requires low complexity and no user interaction, allowing the attacker to elevate privileges with high impacts on confidentiality, integrity, and availability, potentially leading to full system compromise.

Microsoft's advisory provides details on mitigation, available at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21375. Security practitioners should review the update guide for patching instructions and apply relevant updates promptly.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Kernel Streaming WOW Thunk Service Driver Elevation of Privilege Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1036.001 Invalid Code Signature Stealth
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-49138Same product: Microsoft Windows 10 1507
CVE-2025-49732Same product: Microsoft Windows 10 1507
CVE-2025-21240Same product: Microsoft Windows 10 1507
CVE-2025-21223Same product: Microsoft Windows 10 1507
CVE-2025-21286Same product: Microsoft Windows 10 1507
CVE-2025-21371Same product: Microsoft Windows 10 1507
CVE-2025-21305Same product: Microsoft Windows 10 1507
CVE-2024-43627Same product: Microsoft Windows 10 1507
CVE-2025-33064Same product: Microsoft Windows 10 1507
CVE-2025-21411Same product: Microsoft Windows 10 1507

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.20915 · ≤ 10.0.10240.20915
microsoft
windows 10 1607
≤ 10.0.14393.7785 · ≤ 10.0.14393.7785
microsoft
windows 10 1809
≤ 10.0.17763.6893 · ≤ 10.0.17763.6893
microsoft
windows 10 21h2
≤ 10.0.19044.5487
microsoft
windows 10 22h2
≤ 10.0.19045.5487
microsoft
windows 11 22h2
≤ 10.0.22621.4890
microsoft
windows 11 23h2
≤ 10.0.22631.4890
microsoft
windows 11 24h2
≤ 10.0.26100.3194
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+5 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing input validation through analysis or test cases.

SI-10 directly requires validity checks on information inputs, structurally preventing improper or missing validation.

Requiring documented development standards and tools can embed input-validation practices into the engineering process.

Security engineering principles require use of memory-safe constructs and bounds-checked allocation routines that avoid introducing heap overflows.

Memory-protection mechanisms limit the ability of a heap overflow to execute attacker-controlled code or corrupt adjacent structures.

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 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

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

Testing against a defined set of requirements and using code review plus vulnerability scanning forces validation of inputs and handling of unanticipated conditions, reducing the chance that malformed data will be accepted.

prevents

Secure-coding guidelines and mandatory security testing (including code scans) compel developers to validate and sanitize inputs at design and implementation time, lowering the incidence of malformed or malicious data reaching downstream components.

prevents

Mandating input controls that include integrity checks and input validation ensures that untrusted data is examined before use, blocking the root cause of many injection and malformed-data weaknesses.

prevents

Security-by-design principles explicitly call for data validation and sanitization at every layer, reducing the chance that malformed or malicious input will be processed without scrutiny.

prevents

Requiring language-specific secure coding standards, peer review, SAST and documented mitigation of common programming errors forces validation of all inputs before they are trusted.

none

Change management ensures controlled deployment of fixes for discovered heap-overflow vulnerabilities.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

RHEL 8 (1 rule)
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-20

References