Information Leakage / Sibling Domain Enumeration

Description

Sibling domain enumeration is a type of information leakage vulnerability which occurs when an application uses DNS subdomains to identify user accounts or services, and that information is exposed in a way that enables attackers to enumerate valid user accounts and services. According to the Common Weakness Enumeration (CWE) directory, it is classified as CWE-200, which is an information exposure vulnerability. Additionally, the Open Web Application Security Project (OWASP) Testing Guide identifies this vulnerability as one of the many tests that should be performed during a web application assessment.

Risk

Sibling domain enumeration can lead to significant security risks for organizations. Attackers can use this vulnerability to enumerate valid user accounts and services, and then use that information to launch targeted attacks. These attacks can lead to data breaches, system compromise, and other serious security incidents. Organizations should perform regular risk assessments and security testing to identify and mitigate the risk of this vulnerability.

Solution

Organizations should take steps to prevent the enumeration of valid user accounts and services. This can be done by limiting access to the DNS zone file, or by using a different authentication mechanism that does not rely on DNS subdomains. Additionally, organizations should perform regular security tests to identify and address any potential vulnerabilities.