Command and Code Injections

Which of the following scenarios describes a circumstance where code/command execution flaws are most likely to arise?

In the context of web security, what is the primary characteristic of an 'injection' vulnerability?

Consider a PHP application using the following code: system("ping " . $_GET['host']);. If the application lacks proper input sanitization, which of the following inputs for the host parameter represents a command injection vulnerability?

Bash and other system shells interpret certain characters as command separators. Besides the semicolon (;), which of the following is another character that can typically be used to inject commands in a Bash environment?

Within the context of command injection, what is the purpose of 'command substitution'?

In a black-box penetration testing scenario, what initial step is crucial when attempting to identify a command injection vulnerability?

When assessing a white-box environment for potential command injection flaws, what specific elements should security professionals prioritize?

If an application throws errors, what's a useful command to inject to identify code injection?

What is a "pingback" and how can it be used in the context of identifying command injection vulnerabilities?

When attempting to use a pingback to identify command injection flaws, which of the following techniques is most effective for initiating the necessary request to your designated host?

In the context of command injection within Bash, what is the significance of the /dev/tcp/* special files?

How can DNS queries be useful when validating command injection vulnerabilities, and what is a common approach for leveraging them?

Given a Requestbin domain like *.d955264982a2216dc0c4.d.requestbin.net, how would you typically leverage this within a command injection payload to validate the vulnerability?

Within the context of command injection, what is meant by the term 'blind' command injection?

In scenarios involving blind command injection, what is a common technique for exfiltrating the output of the injected command?

When dealing with blind command injection on a Linux system, how can an attacker redirect the output of a command to a publicly accessible file?

When attempting to exfiltrate data via blind command injection, which directories are often writable and publicly reachable, making them prime targets for output redirection?

Regarding out-of-band connections for blind command injection, which of the following techniques is a viable method?

What is a potential command-line instruction to start listening for incoming connections on port 1337, effectively setting up a reverse shell?

What is the primary difference between command injection and code injection vulnerabilities?

In scripting languages, what are the common entry points for code injection vulnerabilities?

Why is it important to know the language the application is written in when trying to find code injections?

Which special characters are commonly used in many languages to detect code injections?

In PHP, which statement is a frequent source of code injection vulnerabilities?

What is local file inclusion (LFI)?

In PHP code injection, what role do the tags <?php ... ?> play?

What is 'file poisoning' in the context of PHP code injection?

What should be the primary focus when creating a payload for file poisoning or file upload attacks?

What broad strategy should be used to prevent most code and command injections?

If avoiding the use of user input is impossible, what mitigations could you take?

In the context of preventing command injection vulnerabilities, what are the key characteristics and limitations of using a 'sandbox'?

An application passes unsanitized user input to a system() call in PHP. The user provides the input example.com && cat /etc/passwd. What is the most likely outcome?

An application uses user-supplied data to construct a filename that is then passed to PHP's include() function. An attacker provides the filename http://evil.com/malicious_code.txt. What vulnerability can this lead to, and what is the most significant risk?

A web application allows users to upload images. However, it does not properly validate the uploaded files. An attacker uploads a file named evil.php containing PHP code. What is the most likely outcome?

A developer uses PHP's escapeshellarg() function to sanitize user input before passing it to a system command. Under what circumstance might this not be sufficient to prevent command injection?

A security analyst discovers that a system is vulnerable to command injection due to the improper use of the system() function in PHP. Which of the following steps would be MOST effective in remediating this vulnerability?

You are tasked with hardening a PHP application against code injection attacks. Which of the following practices is MOST important?