LFI2RCE via Nginx temp files

👉 Overview

👀 What ?

LFI2RCE via Nginx temp files refers to a cybersecurity attack method, a type of Local File Inclusion (LFI) attack, which can lead to Remote Code Execution (RCE). This attack technique exploits vulnerabilities in the Nginx web server software, specifically the way it handles temporary files, allowing an attacker to execute arbitrary code on the target system.

🧐 Why ?

Understanding LFI2RCE via Nginx temp files is crucial because it helps in comprehending how cyber attackers can exploit even small vulnerabilities in a system to gain control over it. As this technique can lead to a full compromise of the target system, it is important for cybersecurity professionals to understand it, to protect their systems from such attacks.

⛏️ How ?

An LFI2RCE via Nginx temp files attack can be executed by an attacker by first finding a Local File Inclusion vulnerability in the target application. Once the vulnerability is discovered, the attacker can manipulate the way Nginx handles temporary files to trick the system into executing arbitrary code. This attack can be prevented by regularly updating the Nginx software, implementing strong input validation and sanitization, and properly configuring the web server.

⏳ When ?

The use of LFI2RCE via Nginx temp files as an attack technique has been prevalent since the early 2000s, with the rise in the usage of the Nginx web server software. The technique is still relevant today, as many servers continue to use Nginx and may have unpatched vulnerabilities.

⚙️ Technical Explanations

In an LFI2RCE via Nginx temp files attack, the attacker takes advantage of a Local File Inclusion vulnerability present in the application running on the Nginx web server. This vulnerability allows the attacker to include and execute local files on the server. The attack becomes possible when Nginx is poorly configured or when certain modules are enabled that shouldn't be. For instance, the FastCGI module, which passes requests from the web server to a FastCGI server, can be manipulated by attackers to execute arbitrary code. This is done by including a file containing the code in a request to the web server, which Nginx then saves as a temporary file. The FastCGI server can then be tricked into executing the code in this temporary file, leading to Remote Code Execution.