Remote Code Execution makes it possible to execute unwanted program code on a computer remotely. Often, security gaps in the operating system and in applications or poorly secured input options are the reason for this security problem. Attackers use the Internet to penetrate systems via remote code execution, execute malware or take over the systems completely.
What is RCE (Remote Code Execution)?
It is the ability to remotely cause a computer or device to execute unintended or unwanted program code over a network such as the Internet. The vulnerability of computers, operating systems, and applications to remote code execution is a common security issue.
Cybercriminals use this vulnerability to execute the malware on other people’s computers, make changes to systems, steal sensitive information, gain administrative privileges, or take over systems completely. They do not need physical access to the computers but carry out their attacks remotely via the Internet.
Devices affected by the remote code execution vulnerability can include PCs, laptops, smartphones, tablets, servers, routers, and many more. Examples of RCE attacks include visiting a crafted website that exploits web browser or operating system vulnerabilities for remote code execution, entering program code via poorly secured web forms, or uploading unwanted files and executing included program code (arbitrary file upload).
Possible sequences of remote code execution
First, an attacker must detect systems or devices that have a vulnerability and are susceptible to remote code execution. To do this, attackers use automated tools that scan systems accessible via the Internet for certain information such as operating system version, browser version, open ports or applications, and software versions used or query these automatically via specially prepared web servers.
Once a system with a vulnerability is found, the attack often proceeds in several stages. First, the attackers obtain increased user rights on the system by executing code. With the help of these rights, further malware can be loaded or the system can be completely taken over. Once a computer has been hijacked in this way, the attackers abuse it for various criminal activities.
Possible causes of remote code execution
The causes of a system’s vulnerability to remote code execution can be manifold. Typical problems and vulnerabilities include poor memory management (creation of buffer overflows), poor protection of input masks or incorrect validation of user input (input of executable commands possible), poor protection against the upload of files with executable program code (arbitrary file upload) and more.
Measures to prevent remote code execution
Effective measures to prevent remote code execution are:
- Regular installation of software updates and security patches (closing known security gaps)
- Reliable protection of user input and file uploads
- Restricting network access to systems remotely (for example, blocking certain ports or IP address ranges)
- Not using outdated operating systems or applications
- Use intrusion detection and prevention systems (IDS and IPS)