MediaTek显示模块越界写入漏洞 (CVE-2025-20777)

/* * CVE-2025-20777 PoC - MediaTek Display Out of Bounds Write * Note: This is a conceptual PoC for educational purposes only. * Requires: Local access with System privilege already obtained. * * This PoC demonstrates the vulnerability pattern where missing bounds * checking in display driver can lead to out-of-bounds memory write. */ #include <stdio.h> #include <stdlib.h> #include <string.h> // Simulated display buffer structure typedef struct { char buffer[256]; unsigned int size; } DisplayBuffer; // Vulnerable function - missing bounds check void display_process_vulnerable(DisplayBuffer *disp, const char *input, unsigned int len) { // VULNERABILITY: No bounds check on len parameter // Should check: if (len > sizeof(disp->buffer)) return ERROR; memcpy(disp->buffer, input, len); disp->size = len; } // Safe version with bounds checking void display_process_safe(DisplayBuffer *disp, const char *input, unsigned int len) { // FIX: Add bounds check if (len > sizeof(disp->buffer)) { printf("[-] Error: Input size exceeds buffer capacity\n"); return; } memcpy(disp->buffer, input, len); disp->size = len; } int main() { DisplayBuffer disp = {0}; char malicious_input[512]; // Prepare malicious input larger than buffer memset(malicious_input, 0x41, sizeof(malicious_input)); printf("[*] Testing CVE-2025-20777 - MediaTek Display OOB Write\n"); printf("[*] Buffer size: %lu bytes\n", sizeof(disp.buffer)); printf("[*] Input size: %lu bytes\n", sizeof(malicious_input)); // Trigger vulnerable function printf("[*] Calling vulnerable function...\n"); display_process_vulnerable(&disp, malicious_input, sizeof(malicious_input)); printf("[+] Triggered out-of-bounds write condition\n"); printf("[!] In real scenario, this could lead to privilege escalation\n"); return 0; }