Flawfinder is a program that examines source code and reports possible security weaknesses (flaws) sorted by risk level. It’s very useful for quickly finding and removing at least some potential security problems before a program is widely released to the public. It’s a static analysis source code auditing tool.

Flawfinder is specifically designed to be easy to install and use. After installing it, at a command line just type:

flawfinder directory_with_source_code

Flawfinder works on Unix-like systems today (it’s been tested on GNU/Linux), and it should be easy to port to Windows systems. It requires Python 1.5 or greater to run (Python 1.3 or earlier won’t work).

Speed

Flawfinder is written in Python, to simplify the task of writing and extending it. Python code is not as fast as C code, but for the task I believe it’s just fine. Flawfinder version 0.12 on a 400Mhz Pentium II system analyzed 51055 lines in 39.7 seconds, resulting in an average of 1285 analyzed lines/second. Flawfinder 1.20 and later will report their speed (in analyzed lines/second) if you’re curious.

How it works

Flawfinder works by using a built-in database of C/C++ functions with well-known problems, such as buffer overflow risks (e.g., strcpy(), strcat(), gets(), sprintf(), and the scanf() family), format string problems ([v][f]printf(), [v]snprintf(), and syslog()), race conditions (such as access(), chown(), chgrp(), chmod(), tmpfile(), tmpnam(), tempnam(), and mktemp()), potential shell metacharacter dangers (most of the exec() family, system(), popen()), and poor random number acquisition (such as random()). The good thing is that you don’t have to create this database – it comes with the tool.

Flawfinder then takes the source code text, and matches the source code text against those names, while ignoring text inside comments and strings (except for flawfinder directives). Flawfinder also knows about gettext (a common library for internationalized programs), and will treat constant strings passed through gettext as though they were constant strings; this reduces the number of false hits in internationalized programs.

You can download Flawfinder here:

flawfinder-1.27.tar.gz

Or read more here.

Bogosec is essentially a tool for finding security vulnerabilities in source code.

BogoSec aims to increase awareness regarding code security vulnerabilities, while encouraging developers to produce more secure code over time. By simplifying the code scanning process, BogoSec achieves a goal of allowing developers to scan their code regularly and more effectively.

BogoSec is a source code metric tool that wraps multiple source code scanners, invokes them on its target code, and produces a final score that approximates the security quality of the code. This article discusses the BogoSec methodology and implementation, and illustrates the output of BogoSec when run on a number of test cases, including Apache Web server, OpenSSH, Sendmail, Perl, and others.

Bogosec seems to use:

• Flawfinder
• ITS4
• RATS

The CERT Coordination Center (CERT/CC) reported 5,990 vulnerabilities in 2005 compared with 171 in 1995. Many software security vulnerabilities occur because of poor programming practices. Some vulnerabilities are algorithmically detectable by static source code scanners designed for identifying potential security issues. As the number and severity of potential security holes per line of code increase, it is reasonable to believe that the overall quality of the source code in terms of security decreases. BogoSec metrics are computed values that attempt to reflect relative ratings of source code security quality for comparative purposes.

The motivation behind BogoSec is to influence developers to produce more secure source code over time. Various scanners exist that point developers to potentially insecure sections of code, but developers are often reluctant to use such scanners because of a seemingly high degree of false positive output as well as the difficulties associated with use. BogoSec attempts to reduce the penalty of false positives while broadening the scope of the source scan by using multiple independent scanners. This produces high-level metrics that allow developers and users alike to comparatively judge the quality of the source code in terms of security.

You can download the full 23 page article here (PDF Warning).

You can find the BogoSec project here.