Category: Writeups

Defcon CTF Quals 2011 – Retro 400

This challenge was on remote exploiting. The binary is for FreeBSD. The program is some kind of a Virtual Machine, with it’s own stack and memory. binary Summary: memory address check mistake, write shellcode and overwrite _exit function pointer

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Defcon CTF Quals 2011 – Binary 500

This challenge was on reverse engineering. The binary is 32bit MZ-PE executable for Windows. binary Summary: reverse engineering, anti-anti-debugging challenge

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Defcon CTF Quals 2011 – Pwnables 100

This challenge was on remote exploiting. The binary is for FreeBSD. binary Summary: buffer overflow, jump to shellcode (bruteforce address)

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Defcon CTF Quals 2011 – Pwnables 200

This challenge was on remote exploiting. The binary is for SunOS (Solaris). binary Summary: shellcoding challenge

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Defcon CTF Quals 2011 – Pwnables 400

This challenge was on remote exploiting. The binary is for Linux, statically linked and stripped. binary Summary: overflow, ROP for execve(“/bin/sh”)

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PlaidCTF 2011 #23 – Exploit Me :p (200)

Category: pwnables It seems like AED also has some plans to raise hacker force! We found this binary as an exploitation practice program in the office, but they forgot to remove the setgid flag on the program. So we can get the secret key! ssh username@a5.amalgamated.biz Username: exp_1 Password: jNKpzFuRLpsIW9xzqNIpCVF1 Summary: .dynamic->FINI overwriting, execl symlink …

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PlaidCTF 2011 #19 – Another small bug (250)

Category: pwnables This time, let’s attack /opt/pctf/z2/exploitme. ssh username@a5.amalgamated.biz Username: z2_1 Password: 29rpJinvpwoI7pzdufQc4h6edzvyh Summary: buffer overflow, static binary binary

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PlaidCTF 2011 #18 – A small bug (250)

Category: pwnables Get access to the key using /opt/pctf/z1/exploitme. ssh username@a5.amalgamated.biz Username: z1_1 Password: GwB4eivw9NTvCjmobw1EnuyqcWfJs Summary: race condition, create a symlink before the file is opened binary

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PlaidCTF 2011 #24 – Calculator (200)

Category: pwnables AED’s summer internship program is notorious for attracting terrible programmers. They’ve resorted to giving them some of the simplest projects to work on. We expect this service that the latest ‘All-Star’ intern worked on all summer is no where near secure. nc a9.amalgamated.biz 60124 Summary: python eval with some filtering

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PlaidCTF 2011 #20 – C++ upgrade (300)

Category: pwnables They have an update for the vulnerable C++ program trying to fix the bug. However, the coders at AED suck and introduced another stupid mistake. Get a shell (and the key, too.) ssh username@a5.amalgamated.biz Username: cpp2_1 Password: zKQaKrdFPSsT6j03XSt31NaT0H Summary: tricky overflow class’ method and exec’ing symlinks binary

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PlaidCTF 2011 #17 – C++5x (300)

Category: pwnables AED decided to use C++ to develop their internal tools. However, they seem to make a mistake one of their new C++ programs. Exploit and get the key! ssh username@a5.amalgamated.biz Username: cpp1_1 Password: IwKheuEHvR1jYXmjIYz8bo8FFe1h8 Summary: tricky overflow class’ method and exec’ing symlinks binary

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PlaidCTF 2011 #25 – PC Rogue (600)

Category: pwnables Amalgamated has banned the use of Solitaire due to loss of productivity. The only employee who would write a new game for everyone only likes ‘retro’ games, and has placed a text-adventure version of pacman on a company server. We don’t believe he could have coded this securely, and the server contains a …

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Nuit du hack 2011 CTF Forensic

Forensic 100 On a dumpe la RAM d’une machine sur laquelle tournait un serveur VNC. Le but est de recupere le mot de passe de ce serveur. * * * We have dumped the RAM of a Machine on which was running a VNC server. The goal is to get the password of that VNC …

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Nuit du hack 2011 CTF Crypto 300

Crypto300 (150 pts.) source Python source code is very clear and concise, and could sometimes bring out lots of clues. This is particularly true for this challenge. Summary: key exchange algorithm based on permutations (braid based cryptography), has some vulnerabilities

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Codegate CTF 2011 Vuln 300

This challenge was an exploitation of suid binary. binary Summary: ROPing buffer overflow with NX and ASLR

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