7th Sharif University CTF

1st challenge, 7th Sharif University Capture The Flag.

Flag = SharifCTF{md5(underlined phrase in the rules page)}

This was a tricky one, after quite bit of research we found out that we had to create an http socket to this url: http://ctf.sharif.edu/ctf7/rules ( and after sending a very specific request of type “GET” we were given an html page. We then had to search for the underlined string which was enclosed in <u> tag (which was: Unless stated otherwise). Then we had to run it through MD5 function to get the flag.


Exploiting CVE-2016-7054, OpenSSL 1.1.0a and b, Heap Buffer Overflow

Couple of days ago Fortinet published a blog post titled “Analysis of OpenSSL ChaCha20-Poly1305 Heap Buffer Overflow (CVE-2016-7054)“. A vulnerability in Openssl library was disclosed affecting versions 1.1.0a and 1.1.0b described as High-Severity Heap Buffer Overflow. Vulnerable code is located in openssl-OpenSSL_1_1_0a\crypto\evp\e_chacha20_poly1305.c file.


بررسی اجمالی الگوریتم‌های MAC، پروتکل TLS و اکسپلویت‌نویسی از آسیب‌پذیری CVE-2016-7054

در این نوشتار به بررسی آسیب پذیری CVE-2016-7054 بر روی کتابخانه OpenSSL نسخه 1.1.0a و 1.1.0b خواهیم پرداخت. به این منظور نخست مفاهیم مورد نیاز در این زمینه را بررسی کرده و سپس به بحث درخصوص روش‌ها و ابزارهای تولید این exploit می‌پردازیم. در صورتی که می‌خواهید مستقیماً به مطالعه آسیب پذیری بپردازید و از مفاهیم پایه ای گذر کنید بر روی این لینک کلیک کنید.


IceCTF 2016

Stage 1 – Time Traveler (Forensics, 45) – Abiusx

The flag has been on the URL before. Using one of the web indexing and caching services, we find the page: https://web.archive.org/web/20160601212948/http://time-traveler.icec.tf/

Stage 1 – Alien Message (Crypto, 40) – Abiusx

It’s FUTURAMA Alienese:


Flag should be:

But it’s not working, I don’t know why.

Ok. It was case sensitive! The size of symbols determine the case: