1. Information Networking Security and Assurance Lab National Chung Cheng University Flawfinder

2. Information Networking Security and Assurance Lab National Chung Cheng University 2 INSA@CCU Contents Overview Environment Install Flawfinder Usage of Flawfinder Example How does Flawfinder Work?

3. Information Networking Security and Assurance Lab National Chung Cheng University 3 INSA@CCU Overview Flawfinder search through C/C++ source code looking for potential security flaw. Flawfinder can integrate well with text editors and integrated development environments.

4. Information Networking Security and Assurance Lab National Chung Cheng University 4 INSA@CCU Install Flawfinder Download Flawfinder http://www.dwheeler.com/flawfinder/

5. Information Networking Security and Assurance Lab National Chung Cheng University 5 INSA@CCU Install Flawfinder (cont.) Unpacking the Package

6. Information Networking Security and Assurance Lab National Chung Cheng University 6 INSA@CCU Usage of Flawfinder Synopsis

7. Information Networking Security and Assurance Lab National Chung Cheng University 7 INSA@CCU Example: wu-ftpd 2.6.0

8. Information Networking Security and Assurance Lab National Chung Cheng University 8 INSA@CCU Example: wu-ftpd 2.6.0 (cont.)

9. Information Networking Security and Assurance Lab National Chung Cheng University 9 INSA@CCU Example: wu-ftpd 2.6.0 (cont.)

10. Information Networking Security and Assurance Lab National Chung Cheng University 10 INSA@CCU Example: wu-ftpd 2.6.0 (cont.)

11. Information Networking Security and Assurance Lab National Chung Cheng University 11 INSA@CCU How does Flawfinder Work? Flawfinder works by using a built-in database of C/C++ functions with well-known problems.  Buffer Overflow Risks strcpy(), strcat(), gets(), sprintf(), and the scanf() family  Format String Problems [v][f]printf(), [v]snprintf(), and syslog()

12. Information Networking Security and Assurance Lab National Chung Cheng University 12 INSA@CCU How does Flawfinder Work? (cont.)  Race Conditions access(), chown(), chgrp(), chmod(), tmpfile(), tmpnam(), tempnam(), and mktemp()  Potential Shell Meta-character Dangers Most of the exec() family, system(), popen()  Poor Random Number Acquisition Such as random()

13. Information Networking Security and Assurance Lab National Chung Cheng University 13 INSA@CCU Risk in the Hitlist