March 13, 2018

How to assemble a GSM phone based on SDR

The smartphones so familiar to most of us contain an entire communication module separate from the main CPU. This module is what makes a "smartphone" a "phone." Regardless of whether the phone's user-facing operating system is Android or iOS, the module usually runs a proprietary closed-source operating system and handles all voice calls, SMS messages, and mobile Internet traffic.

Of course, open-source projects are more interesting to security researchers than closed-source ones. The ability to look under the hood and see how a particular program component works makes it possible to find and fix errors, plus verify that undocumented functionality is not present. As a pleasant bonus, access to source code helps novice developers to learn from colleagues and make contributions of their own.

March 5, 2018

The First Rule of Mobile World Congress Is: You Do Not Show Anyone Your Mobile World Congress Badge

The biggest event of the telecom industry attracted particularly wide media coverage this year: the King of Spain personally arrived in Barcelona for the opening of the annual Mobile World Congress (MWC 2018), which caused a wave of protests by supporters of the region's independence from Madrid. As a result, newspaper front pages and TV channel prime time are all taken by high tech and telecom innovations against the backdrop of protesting crowds. And it is recommended that all participants and visitors to the Congress should not wear a badge outside the venue for greater security.

February 22, 2018

New bypass and protection techniques for ASLR on Linux

By Ilya Smith (@blackzert), Positive Technologies researcher

0. Abstract

The Linux kernel is used on systems of all kinds throughout the world: servers, user workstations, mobile platforms (Android), and smart devices. Over the life of Linux, many new protection mechanisms have been added both to the kernel itself and to user applications. These mechanisms include address space layout randomization (ASLR) and stack canaries, which complicate attempts to exploit vulnerabilities in applications.