Listen to this Post
Windows 11 Win32K subsystem contains a local information disclosure vulnerability.
The flaw resides in the user mode mapping of the desktop heap.
Specifically, a raw kernel session pool pointer is exposed at offset 0x100.
An authenticated local attacker can read this memory address directly.
This pointer exposes the base address of the desktop heap in kernel space.
Kernel Address Space Layout Randomization (KASLR) is bypassed via this leak.
The issue affects low-integrity processes and AppContainer environments.
Even zero-capability sandboxed processes can access the leaked QWORD.
The read operation targets the mapped memory region of the desktop heap.
By extracting the pointer, attackers map internal kernel structures.
The user32.dll export gSharedInfo helps resolve window object addresses.
Combining the leaked desktop heap base with handle entries locates windows.
This turns a simple memory leak into a reliable address oracle.
Attackers chain this information disclosure to support privilege escalation.
The vulnerability requires local access to execute the PoC script.
No remote vector exists for exploiting this specific Win32K flaw.
Microsoft addressed the issue in recent cumulative security updates.
Understanding the mechanics highlights risks in shared user-kernel mappings.
Memory exposure in subsystem heaps weakens overall operating system isolation.
Researchers identified the anomaly during analysis of insider builds.
Mitigation relies entirely on applying official vendor security patches.
The simplicity of the read instruction demonstrates subtle design oversights.
Kernel pointer leakage remains a classic stepping stone for local exploits.
Securing local execution environments prevents unauthorized subsystem interaction.
DailyCVE Form:
Platform: Windows 11
Version: Version 24H2
Vulnerability: Information Disclosure
Severity: Low Severity
date: July 2026
Prediction: Patched In July
What Undercode Say
Analysis of the Win32K desktop heap mapping reveals an unprivileged kernel memory exposure. The vulnerability allows local code execution contexts, including low-integrity sandboxes, to read raw pointers from shared memory regions.
Bash and verification commands related to the analysis:
Check system build and environment winver systeminfo | findstr /B /C:"OS Name" /C:"OS Version" Compile and run local PoC harness cl /W4 poc.c poc.exe
Exploit: (Educational Purposes!)
The proof-of-concept snippet targets the mapped desktop heap to extract the raw kernel pointer at offset 0x100:
include <windows.h>
include <stdio.h>
int main() {
LPVOID desktop_heap = GetProcessWindowStation();
if (desktop_heap) {
ULONG64 leaked = (ULONG64 )((PBYTE)desktop_heap + 0x100);
printf("Leaked Kernel Pointer: 0x%llx\n", leaked);
}
return 0;
}
Protection: from this CVE
Apply the official cumulative security updates provided by Microsoft for Windows 11 and Windows Server.
Enforce strict least-privilege principles across all user sessions and local environments.
Monitor endpoint telemetry for unauthorized probing of GDI and USER kernel objects.
Restrict interactive logon rights to minimize local attack surfaces on multi-user systems.
Impact:
An authenticated local attacker can exploit this vulnerability to disclose sensitive kernel memory addresses. This information disclosure bypasses Kernel Address Space Layout Randomization (KASLR), facilitating follow-on local privilege escalation exploit chains.
🎯Let’s Practice Exploiting & Learn Patching For Free:
🎓 Live Courses & Certifications:
Join Undercode Academy for Verified Certifications
🚀 Request a Custom Project:
Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
