CompTIA PenTest+ (PT0-003) — Question 187

A penetration tester is investigating a buffer overflow on the myfile binary. The tester wants to send a payload to help identify the exact offset to inject the memory address to take control of the buffer.

Which of the following would allow the penetration tester to quickly identify the offset?

Answer options

• A. ./myfile < $(printf ‘A%.0s’ {1.1000}
• B. echo ‘A’ |head -n 1000 |tr -d ‘\n’ | ./myfile
• C. python -c ‘print(“A”*1000)’ > test.txt; cat test.txt >./myfile
• D. ./pattern_create.rb 1000 > test.txt; ./myfile < test.txt

Correct answer: D

Explanation

The correct answer, D, utilizes the pattern_create.rb script to generate a unique pattern of 1000 characters, allowing the tester to identify the exact offset once the application crashes. The other options either do not create a unique pattern or do not adequately test the overflow scenario, making them less effective for identifying the offset.