Stack-Based Buffer Overflow in Windows win32k.sys (CVE‑2010‑4398) Enables UAC Bypass
What It Is – A stack‑based buffer overflow in the RtlQueryRegistryValues function of win32k.sys on Microsoft Windows allows a local user to corrupt kernel memory, elevate privileges, and bypass User Account Control (UAC).
Exploitability – Publicly disclosed in 2010; proof‑of‑concept code exists and the vulnerability is exploitable on unpatched systems. CVSS v3.1 base score ≈ 7.8 (High).
Affected Products – Microsoft Windows operating systems that include the vulnerable win32k.sys driver (all supported versions prior to the security update released by Microsoft).
Why It Matters for Trust & Control Assurance
- Demonstrates the need for access‑control controls that enforce least‑privilege and monitor privileged‑account activity.
- Highlights the importance of continuous patch management as evidence of due‑diligence in an audit trail.
- Shows that without proper kernel‑level exploit mitigation (DEP, ASLR, CFG), organizations cannot reliably attest to the integrity of their endpoint environment—something enterprise buyers increasingly demand.
Recommended Actions
- Deploy Microsoft’s security update that resolves CVE‑2010‑4398 on all Windows endpoints.
- Verify that exploit‑mitigation features (DEP, ASLR, Control Flow Guard) are enabled and enforced.
- Add the patch status to your continuous configuration monitoring pipeline to generate real‑time compliance evidence.
- Review privileged‑account logs for any anomalous activity that could indicate exploitation attempts.
Source: CISA KEV – CVE‑2010‑4398