A flaw was found in the default configuration of dnsmasq, as shipped with Fedora versions prior to 31 and in all versions Red Hat Enterprise Linux, where it listens on any interface and accepts queries from addresses outside of its local subnet. In particular, the option local-service is not enabled. Running dnsmasq in this manner may inadvertently make it an open resolver accessible from any address on the internet. This flaw allows an attacker to conduct a Distributed Denial of Service (DDoS) against other systems.
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Fedora | Fedoraproject | * | 31 (excluding) |
| Dnsmasq | Ubuntu | esm-infra-legacy/trusty | * |
| Dnsmasq | Ubuntu | precise/esm | * |
| Dnsmasq | Ubuntu | trusty | * |
| Dnsmasq | Ubuntu | trusty/esm | * |
| Dnsmasq | Ubuntu | upstream | * |
Access control involves the use of several protection mechanisms such as:
When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses: