Files
OffSec-CTF/canary/05_cafe_menu/main.c
2026-05-10 20:42:33 +02:00

45 lines
903 B
C

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static void setup(void) {
setvbuf(stdin, NULL, _IONBF, 0);
setvbuf(stdout, NULL, _IONBF, 0);
setvbuf(stderr, NULL, _IONBF, 0);
}
__attribute__((noreturn)) static void win(void) {
puts("Chef's special unlocked!");
char *argv[] = {"/bin/sh", NULL};
execve("/bin/sh", argv, NULL);
_exit(0);
}
static void vuln(void) {
struct {
char menu[48];
volatile unsigned int idx;
} data;
data.idx = 0;
printf("Enter today's specials (send 0xff to finish):\n");
while (data.idx < 200) {
char c;
if (read(STDIN_FILENO, &c, 1) != 1) break;
if ((unsigned char)c == 0xff) break;
data.menu[data.idx] = c;
data.idx++;
}
printf("Menu updated!\n");
}
int main(void) {
setup();
printf("Welcome to the Cafe!\n");
vuln();
return 0;
}