Zero-Day Advisory

Fortinet Discovers NitroPDF Reader Use After Free Vulnerability


Fortinet's FortiGuard Labs has discovered a Use-After-Free vulnerability in Nitro's NitroPDF Reader software.

Nitro Software, Inc. develops commercial software used to create, edit, sign, and secure Portable Document Format (PDF) files and digital documents. The Nitro ecosystem consists of Nitro Pro, Nitro Cloud, Nitro Reader, and a suite of document conversion sites.

A Use-After-Free vulnerability has been discovered in NitroPDF Reader. The vulnerability exists due to an error while the vulnerable software attempts to open a specially crafted PDF file. It could lead to remote code execution.


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

Released Jan 16, 2018

Since NitroPDF Reader is discontinued, and is no longer supported by Nitro Software, we suggest users uninstalling it right away.

Additional Information

Fortinet reported the vulnerability to Nitro Software on December 13, 2017.

Nitro Software replied "The NitroPDF Reader free product is end-of-life, discontinued, and is no longer supported" on December 14, 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.