Teaser CTF 2015 writeup(So easy, power level)

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Teaser CTF is launched by Dragon Sector, is a Polish security Capture The Flag team. It was created in February 2013 and currently has 13 active members.

I solved two challenge in the first evening(so easy, power level) and tried to solves the pwnable challenge quine on Sunday Morning but failed, I found a write-any-where vulnerability but I didn’t see how to exploit. Continue reading “Teaser CTF 2015 writeup(So easy, power level)”

Install ropc(based on bap 0.4) on ubuntu 14.04

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I wanted to play with ropc and died a little in installing ropc. Firstly we have to install BAP 0.4. To compile BAP, we need to install ocaml 3.12.1 from source(because ocaml 4.0 can not compile BAP 0.4). Then we need to install camomile from source.(again the default apt-get camomile version failed in the compilation).

add configure.ac:

PS: the following package should be installed before compiling bap0.4.

another issue is :

It’s such a pain that a end up installing bap using opam…


Plaid CTF 2015 writeup(prodmanager, clifford, ebp, unknown)

Categories CTF

1. prodmanager(180 points)

prodmanager is a product manage system. After a short investigation of the source code, I found that there is a UAF vulnerability of double linked list. Actually the program did not manage product list and lowerest price list properly, an item which is freed in the product list still presents in the lowerest price list. Continue reading “Plaid CTF 2015 writeup(prodmanager, clifford, ebp, unknown)”

0CTF-2015 freenote: playing with malloc library

Categories CTF

I spent several hours on this challenge, the logic of this program is simple and an information leakage vulnerability was discovered. But I was not familiar with malloc’s heap management scheme and failed to exploit this vulnerability.

The vulnerability has its root in no  '\0'  was appended to the input note, it’s possible to leak a heap pointer by crafting a string before the heap pointer. But I didn’t know how then, after reading this and this writeup I finally figured out how to do this. This and this also help a lot to understand heap exploitation technique. This article is a record for reference. Continue reading “0CTF-2015 freenote: playing with malloc library”

BCTF 2015 pwn challenge: zhongguancun

Categories CTF

The general idea to pwn this toy online store system is as following, firstly we need to find a control flow hijack vulnerability which in this case is a vtable hijack based on heap buffer overflow, secondly we will bypass all the integrity checks in the program and the memory defenses(e.g. ASLR) to call “system(“sh”)” in libc.

Continue reading “BCTF 2015 pwn challenge: zhongguancun”