What is Privilege Escalation Vulnerability ?
Privilege escalation is a security vulnerability that allows attackers to gain higher user privileges. This can result in unauthorized access and manipulation of sensitive data.
The Story
Asem Eleraky, a security researcher also known as Melotover, has discovered a way to exploit a Reflected XSS vulnerability to gain Super Admin privileges. The researcher found the vulnerability while exploring the subdomain of a private program, referred to as example.com.
Asem attempted to exploit the vulnerability by adding javascript code to the referer parameter of the URL, which had no validation, and successfully found a Reflected XSS vulnerability of P3 severity.
Further exploration led to the discovery of a function that allows the sending of an invitation to add a user as a Super Admin privileged user.
To exploit the function, Asem had to gather important information such as the PID of the current user, the X-Example-CSRF header with a CSRF value, and the JSON format request body containing the email of the user to be invited, as well as the role of the invited user. However, this information was missing, so the researcher had to dig deeper to gather the necessary information..
Asem found that the cookie parameters had useful information like the PID of the user in the USER_ID parameter and the CSRF value in the example-csrf cookie parameter.
With all the necessary information, Asem wrote a javascript payload that made the whole process of the exploit possible. The payload was used to send a link to the victim, and when the victim clicked on the link, Asem gained Super Admin privileges on the victim’s account.
How to Prevent Privilege Escalation Vulnerability?
To prevent this type of vulnerability, here are some steps that can be taken:
- Regularly update and patch software and applications to ensure that known vulnerabilities are addressed.
- Implement strong access controls and permissions management, such as least privilege, role-based access control (RBAC), and separation of duties.
- Use secure coding practices to avoid common programming errors that can lead to privilege escalation vulnerabilities, such as input validation, output encoding, and proper error handling.
- Conduct regular security assessments and penetration testing to identify potential vulnerabilities and address them before they can be exploited by attackers.
- Implement network segmentation and isolation to limit the impact of a potential attack.
- Monitor system logs and user activity to detect and respond to potential privilege escalation attempts.
By following these steps, organizations can help reduce the risk of privilege escalation vulnerabilities and protect their systems and data from unauthorized access and exploitation.
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