목록picoCTF 2018/Binary Exploitation (5)
Bace
picoCTF 2018 - buffer overflow 2
주어진 소스를 보면 #include #include #include #include #include #define BUFSIZE 100 #define FLAGSIZE 64 void win(unsigned int arg1, unsigned int arg2) { char buf[FLAGSIZE]; FILE *f = fopen("flag.txt","r"); if (f == NULL) { printf("Flag File is Missing. Problem is Misconfigured, please contact an Admin if you are running this on the shell server.\n"); exit(0); } fgets(buf,FLAGSIZE,f); if (arg1 != 0xDEADB..
picoCTF 2018 - shellcode
주어진 소스파일을 보면 #include #include #include #include #include #define BUFSIZE 148 #define FLAGSIZE 128 void vuln(char *buf){ gets(buf); puts(buf); } int main(int argc, char **argv){ setvbuf(stdout, NULL, _IONBF, 0); // Set the gid to the effective gid // this prevents /bin/sh from dropping the privileges gid_t gid = getegid(); setresgid(gid, gid, gid); char buf[BUFSIZE]; puts("Enter a string!"); vul..
picoCTF 2018 - leak me
주어진 주소와 포트에 접속하면 다음과 같이 나온다. 이름과 password를 치면 맞지 않은 password라고 뜬다. 주어진 소스를 봐보았다. #include #include #include #include #include int flag() { char flag[48]; FILE *file; file = fopen("flag.txt", "r"); if (file == NULL) { printf("Flag File is Missing. Problem is Misconfigured, please contact an Admin if you are running this on the shell server.\n"); exit(0); } fgets(flag, sizeof(flag), file); printf(..
picoCTF 2018 - buffer overflow 1
소스를 봐보았다. #include #include #include #include #include #include "asm.h" #define BUFSIZE 32 #define FLAGSIZE 64 void win() { char buf[FLAGSIZE]; FILE *f = fopen("flag.txt","r"); if (f == NULL) { printf("Flag File is Missing. Problem is Misconfigured, please contact an Admin if you are running this on the shell server.\n"); exit(0); } fgets(buf,FLAGSIZE,f); printf(buf); } void vuln(){ char buf[BUF..