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200-201 · Question #514

If a web server accepts input from the user and passes it to a bash shell, to which attack method is it vulnerable?

The correct answer is D. command injection. Command injection occurs when a web server accepts user input and passes it to a shell (such as Bash) without proper sanitization. This allows attackers to execute arbitrary system commands by injecting malicious input. For example, if a web application allows users to enter a…

Submitted by yousef_jo· Mar 6, 2026Security Concepts

Question

If a web server accepts input from the user and passes it to a bash shell, to which attack method is it vulnerable?

Options

  • Ainput validation
  • Bhash collision
  • Cinteger overflow
  • Dcommand injection

How the community answered

(20 responses)
  • A
    5% (1)
  • B
    15% (3)
  • C
    5% (1)
  • D
    75% (15)

Explanation

Command injection occurs when a web server accepts user input and passes it to a shell (such as Bash) without proper sanitization. This allows attackers to execute arbitrary system commands by injecting malicious input. For example, if a web application allows users to enter a filename but fails to validate input, an attacker could submit: filename.txt; rm -rf / This would execute the rm -rf / command, potentially deleting critical system files. - Input validation is a mitigation strategy, not an attack method. - Hash collision is related to cryptographic weaknesses, not shell execution. - Integer overflow exploits numerical data limits, not command execution. Since command injection is the attack method that exploits unsanitized input passed to a shell.

Topics

#command injection#web vulnerabilities#input validation

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