CISA and FBI Issue Alert on OS Command Injection Vulnerabilities
CISA and FBI issued a critical advisory on July 10, 2024, urging software companies to review their products and eliminate OS command injection vulnerabilities at the source. This urgent call comes in the wake of recent attacks that exploited several OS command injection flaws (CVE-2024-20399, CVE-2024-3400, and CVE-2024-21887) to compromise network edged devices from prominent vendors, such as Cisco, Palo Alto, and Ivanti.
What is OS Command Injection?
OS command injection is a type of vulnerability that allows attackers to execute arbitrary operating system (OS) commands on the host system through a vulnerable application. These vulnerabilities occur when software fails to properly validate and sanitize user input used in constructing commands for execution on the underlying operating system. This oversight can allow attackers to execute arbitrary and potentially harmful commands, posing significant risks to users and organizations.
As stated in the joint advisory, “Designing and developing software that trusts user input without proper validation or sanitization can allow threat actors to execute malicious commands, putting customers at risk.”
Prevention and Best Practices
CISA emphasizes several key measures to prevent OS command injection vulnerabilities:
Use Built-in Library Functions: Whenever possible, developers should use built-in library functions that separate commands from their arguments, rather than constructing raw strings fed into general-purpose system commands.
Input Parameterization: This technique involves keeping data separate from commands and ensuring all user-supplied input is thoroughly validated and sanitized.
Limit Command Construction: Restrict the parts of commands that are constructed from user input to only what is necessary, minimizing the risk of malicious input being executed.
Role of Tech Leaders
Tech leaders play a crucial role in ensuring software security. They should be actively involved in the development process, advocating for the use of functions that generate commands safely while maintaining the intended syntax and arguments. Additionally, they should:
Review Threat Models: Continuously analyze and update threat models to reflect emerging threats and vulnerabilities.
Use Modern Component Libraries: Adopt and maintain up-to-date component libraries that are designed with security in mind.
Conduct Code Reviews: Implement rigorous code review processes to identify and remediate security weaknesses early in the development lifecycle.
Implement Rigorous Testing: Ensure thorough product testing to validate the security and quality of the code.
Final Thoughts
Despite being a well-known and preventable issue, OS command injection vulnerabilities continue to be prevalent, ranking fifth in MITRE’s top 25 most dangerous software weaknesses. The persistent nature of these vulnerabilities highlights the importance of adopting Secure by Design principles and robust preventive measures. In recent months, CISA has issued multiple “Secure by Design” alerts, urging tech executives and developers to eliminate path traversal and SQL injection (SQLi) vulnerabilities.
The sources for this article include a story from BleepingComputer.