Cyber Resilience

CVE-2025-49730

Memory Safety in Microsoft Windows Server 2008 r2

Published
08 July 2025
Modified
17 June 2026
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 0.0060 46th percentile
Risk Priority 62 floored blend · peak EPSS

Summary

CVE-2025-49730 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 46th 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 AC-25 (Reference Monitor) and SA-11 (Developer Testing and Evaluation) — 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.

The vulnerability CVE-2025-49730 is a time-of-check time-of-use (TOCTOU) race condition in the Microsoft Windows QoS scheduler. It is tracked under CWE-367 and CWE-122 and carries a CVSS 3.1 base score of 7.8 reflecting local attack vector, low complexity, and high impact on confidentiality, integrity, and availability.

An authorized local attacker can exploit the race condition to elevate privileges on the affected Windows system, achieving arbitrary code execution or full administrative access without user interaction.

The Microsoft Security Response Center advisory recommends applying the security updates released for the QoS scheduler component to eliminate the TOCTOU window. The associated EPSS score remains flat at 0.0351 with no material increase observed since disclosure.

EU & UK References

Vulnerability Data

Time-of-check time-of-use (toctou) race condition in Microsoft Windows QoS scheduler allows an authorized attacker to elevate privileges locally.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1034 Path Interception Persistence
**This technique has been deprecated.
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.
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-2026-20809Same product: Microsoft Windows 10 1607
CVE-2025-54895Same product: Microsoft Windows 10 1507
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

Affected Assets

microsoft
windows 10 1507
≤ 10.0.10240.21073 · ≤ 10.0.10240.21073
microsoft
windows 10 1607
≤ 10.0.14393.8246 · ≤ 10.0.14393.8246
microsoft
windows 10 1809
≤ 10.0.17763.7558 · ≤ 10.0.17763.7558
microsoft
windows 10 21h2
≤ 10.0.19044.6093
microsoft
windows 10 22h2
≤ 10.0.19045.6093
microsoft
windows 11 22h2
≤ 10.0.22621.5624
microsoft
windows 11 23h2
≤ 10.0.22631.5624
microsoft
windows 11 24h2
≤ 10.0.26100.4652
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)

Validate
Prove the fix (OWASP ASVS)
  • V1.4.1
  • V15.4.2
  • V17.2.6

Mitigating Controls (NIST 800-53 r5) AI

A reference monitor that is always invoked and analyzable structurally eliminates the non-atomic check-then-use pattern underlying TOCTOU.

Developer testing and evaluation (including fuzzing and memory-error detectors) can discover heap overflows after they have been coded.

Input validation enforces bounds checking on data written to heap buffers, directly stopping the overflow condition from being introduced.

Access enforcement that performs an atomic check-and-use decision directly stops the window in which a TOCTOU race can be exploited.

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

Process isolation limits the blast radius of a successful TOCTOU exploitation but does not remove the race itself.

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

Security testing in development and acceptance can detect heap overflows before release.

prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

none

Reliable, synchronized time across systems narrows the exploitable window in which a resource state can change between a security check and its use.

References