Remote code execution is one of the most critical vulnerabilities that can be found in an application. It is fatal to the application as well as the users alike as it allows the execution of malicious code in the application server.
RCE is caused by attackers creating malicious code and injecting it into the server via input points. The server unknowingly executes the commands, and this allows an attacker to gain access to the system.
After gaining access, the attacker might try to escalate privileges. This can completely compromise a vulnerable system.
Source code from third-parties applications, libraries, and plugins might be utilizing functions prone to RCE vulnerability. A recent case was with ImageMagick. ImageMagick is a well-known image processing library utilized by thousands of websites. Unfortunately, it had a RCE vulnerability, named ImageTragick.
Remote code execution can leave the application and users at a high-risk, resulting in an impact on confidentiality, and integrity of data. An attacker who can execute commands with system or server privileges can:
Add, read, modify, delete files
Change access privileges
Turn on and off configurations and services
Communicate to other servers
It is necessary to focus on the importance of having robust security measures in place. We should always be aware of how our server handles user-provided information. We can mitigate remote code execution by using the following techniques:
Timely patching or installation of software updates is an essential preventative measure
Avoid using user input inside the evaluated code
Don’t use functions such as eval at all
Use safe practices for secure file uploads and never allow a user to decide the extension or content of files on the web server