C/C++ Secure Coding

Advanced C/C++

The training explains in details the mechanisms underlying typical C/C++ security relevant programming bugs – the common security vulnerabilities. The root causes of the problems are explained through a number of easy-to-understand source code examples, which at the same time make clear how to find and correct these problems in practice. The real strength of the course lays in numerous hands-one exercises, which help the participants understand how easy it is to exploit these vulnerabilities by the attackers.

The course also gives an overview of practical protection methods that can be applied at different levels (hardware components, the operating system, programming languages, the compiler, the source code or in production) to prevent the occurrence of the various bugs, to detect them during development and before market launch, or to prevent their exploitation during system operation. Through exercises specially tailored to these mitigation techniques participants can learn how simple – and moreover cheap – it is to get rid of various security problems.

Common security vulnerabilities:

• Buffer Overflow (BOF), stack and heap overflow
• Heartbleed
• array indexing problems, the unicode bug
• missing or improper input validation, integer problems, widthness bug, signedness bug, arithmetic overflow, integer mishandling case study – Android Stagefright bug, Print format string bug (PFS), Directory Traversal Vulnerability (DTV)
• improper use of security features, weak randomness, password management
• error handling-related problems
• race conditions, Time-of-Checking- to-Time-of-Usage (TOCTTOU) vulnerability, safe signal handling, and many more...

Mitigation techniques:

• Never eXecute (NX bit) access mode of Virtual Memory Management (VMM)
• Address Space Layout Randomization (ASLR) – PaX, ExecShield
• Stack smashing protection (SSP), StackGuard, ProPolice

Exercises:

• exploiting stack overflow – executing shell codes
• applying protection techniques (stack smashing protection, non-executable stack and heap, ASLR)
• circumventing protections with NOP sledding, Return-to-libc attack, Return Oriented Programming (ROP)
• understanding Shellshock
• understanding integer problems
• applying mitigation techniques
• crafting a print format attack string – write-what-where (WWW) possibilities
• password management; problems of exception-based error handling
• exploiting race conditions with symlinks
• and many spot- and-correct-the-bug exercises