Zero-Day Advisory

Fortinet Discovers Foxit Reader And PhantomPDF Digital Signature Handling Memory Corruption Vulnerability


Fortinet's FortiGuard Labs has discovered a memory corruption vulnerability in Foxit Reader and PhantomPDF.
Foxit Reader is a small, lightning fast, and feature rich PDF viewer which allows users to create, open, view, sign, and print any PDF file. Foxit Reader is built upon the industry's fastest and most accurate PDF rendering engine, providing users with the best PDF viewing and printing experience.
Foxit PhantomPDF is the industry's premiere PDF editor; making editing PDF files easier than ever before to deliver professional looking PDF documents in no time at all. Its PDF editing capabilities provide capabilities similar to that of word processing software. The PDF editor automatically identifies text boxes and allows users to paragraph edit within that text box.
The discovered vulnerability is caused due to insufficient validation when verifying the digital signature in Foxit Reader and PhantomPDF. Attackers could exploit this vulnerability to cause a denial of service (memory corruption) or potentially execute arbitrary code.


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

Released May 20, 2015
Users should apply the solution provided by Foxit Software.

Additional Information

The fields '/ByteRange' and 'adbe.pkcs7.detached' in PDF file are used for digital signature. A memory corruption issue is caused in Foxit Reader and PhantomPDF when they are changed to malformed values.


This vulnerability was discovered by Kai Lu 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.