Sep 19, 2016

Last weekend, we ran the annual CSAW CTF qualification round. After a wonderful competition, we’ve released all the problems (along with Dockerfiles for deployment) to the public.

Jun 11, 2016

Last year, we had many ctf teams from around the world compete in the annual CSAW CTF. This event is geared toward college undergradates, however it is open to anyone who wishes to play.

Oct 3, 2015

After creating an account on the site and logging in, we notice pretty quickly that trying to set our profile image URL to an invalid URL returns a python error

Oct 3, 2015

After quickly looking through the .pcap, we find two things: a python source file, and a large b64 string (‘2Mk16Sk5iakYx…’)

Oct 3, 2015

We’re given a .tar.xz which contains a partially corrupted git repo. Running git log reveals 4 commits, which all primarily build out one main .c file:

Oct 3, 2015

After browsing around the home page of the website given, we notice 2 suspect things: password MD5s are computed client side, and there is a version number at the bottom of the page. After inspecting in chrome dev tools, we see that the version number is dynamically pulled from /.git/refs/heads/master, meaning that the site’s .git is publically accessible. However, while we can read files, directory listings are turned off. After researching the basics of how git works, we grab /.git/index which contains the filenames and sha1 hashes of all files in the repo. Running this through a git index parser (e.g. gin), we get a list of all the files and hashes:

Sep 28, 2015

TL; DR

• Overflow

Sep 28, 2015

TL; DR

• Overflow
• Uninitialized Variable
• Format String