Protect Your DNS Queries: Unbound DNS Resolver Vulnerability Allows Manipulation

CVSScvssV3_1: 8

Unbound is a popular open-source recursive DNS resolver used by many Linux distributions and services. A vulnerability was discovered in Unbound that could allow an attacker to manipulate its configuration if they have access to the local system.

Due to incorrect file permissions, any process on the system could connect to Unbound’s management port and modify settings like forwarders. This means an attacker could change the DNS servers Unbound queries to track a user’s DNS lookups. They could also disrupt DNS resolution by modifying settings.

The attack scenario is that malware or any other process gains access to the system where Unbound is running. It then connects to the management port and sends configuration changes. This allows the attacker to effectively intercept and monitor a user’s DNS queries without their knowledge.

If you have Unbound installed, you should update it to the latest version immediately. Administrators should also review the configuration and ensure only trusted processes can access the management port. Users should keep their systems updated with the latest patches and be cautious of unknown processes requesting network or system privileges. Practicing good security hygiene can help prevent attackers from exploiting vulnerabilities like this.