Zero-Day Advisory

Fortinet Discovers PowerDNS Recursor HTML/Script Injection Vulnerability


Fortinet's FortiGuard Labs has discovered a HTML/Script injection vulnerability in the web interface of PowerDNS Recursor.

PowerDNS Recursor is a high-end, high-performance resolving name server which powers the DNS resolution of at least a hundred million subscribers. Utilizing multiple processors and supporting the same powerful scripting ability of the Authoritative Server, Recursor delivers top performance while retaining the flexibility modern DNS deployments require.

A HTML/Script injection vulnerability has been found in the web interface of PowerDNS Recursor, where the qname of DNS queries was displayed without any escaping, allowing a remote attacker to inject HTML/Javascript code into the web interface, altering the content. When victims access the web interface, the injected HTML/Script code will be automatically executed within the context of their browser.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Oct 23, 2017

Users should apply the solution provided by PowerDNS.

Additional Information

Fortinet reported the vulnerability to PowerDNS on Aug. 7, 2017.

PowerDNS confirmed the vulnerability on Aug. 8, 2017.

PowerDNS patched the vulnerability on Nov. 27, 2017.


This vulnerability was discovered by Chris Navarrete of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.