Measuring OS X Meltdown Patches Performance

Happy New Year and happy ten year anniversary to this blog, which I totally forgot back in October :-/. Blogging activity here has been so slow that I almost forgot how to work with Hugo. We started 2018 with heavy speculation on critical CPU bugs that were under disclosure embargo. Luckily for us, Google decided to break the embargo and release some proper information about the bugs so speculation could stop and facts could finally flow in. The merits or not of disclosure embargos deserve a serious discussion but this post is not the place for it. This one was for sure a huge mess. The world was finally introduced to Meltdown and Spectre. ...

January 7, 2018 · 18 min · 3691 words

Exploiting CVE-2017-5123

This is a guest post by a young and talented Portuguese exploiter, Federico Bento. He won this year’s Pwnie for Epic Achievement exploiting TIOCSTI ioctl. Days ago he posted a video demonstrating an exploit for CVE-2017-5123 and luckly for you I managed to convince him to do a write-up about it. I hope you enjoy his work. Thanks Federico! ...

November 7, 2017 · 10 min · 1981 words

Shut up snitch! – reverse engineering and exploiting a critical Little Snitch vulnerability

Little Snitch was among the first software packages I tried to reverse and crack when I started using Macs. In the past I reported some weaknesses related to their licensing scheme but I never audited their kernel code since I am not a fan of IOKit reversing. The upcoming DEF CON presentation on Little Snitch re-sparked my curiosity last week and it was finally time to give the firewall a closer look. ...

July 22, 2016 · 35 min · 7450 words

SyScan360 Singapore 2016 slides and exploit code

The exploit for the bug I presented last March at SyScan360 is today one year old so I decided to release it. I wasn’t sure if I should do it or not since it can be used in the wild but Google Project Zero also released a working version so it doesn’t really make a difference. I’m also publishing here the final version of the slides that differ slightly from the version made available at the corporate blog....

April 27, 2016 · 2 min · 242 words

Reversing Apple’s syslogd bug

Two days ago El Capitan 10.11.3 was released together with security updates for Yosemite and Mavericks. The bulletin available here describes nine security issues, most of them related to kernel or IOKit drivers. The last security issue is about a memory corruption issue on syslog that could lead to arbitratry code execution with root privileges. I was quite curious about this bug mostly because it involved syslogd, a logging daemon....

January 22, 2016 · 7 min · 1490 words