Zero-Day Advisory

Fortinet Discovers Adobe Acrobat Reader CoolType Heap Overflow Vulnerability

Summary

Fortinet's FortiGuard Labs has discovered a heap overflow vulnerability in Adobe Acrobat and Reader.
Adobe Acrobat and Reader are products of Adobe Systems. They are developed to view, create, manipulate, print and manage files in Portable Document Format (PDF). They are the most popular PDF applications. The freeware Adobe Reader, available for several desktop and mobile platforms, can view, print and annotate PDF files. The commercial proprietary Acrobat, available for Microsoft Windows and OS X only, can also create, edit, convert, digitally sign, encrypt, export and publish PDF files.

A heap overflow vulnerability has been discovered in Acrobat and Reader. The vulnerability is caused by a crafted PDF file which causes an out of bounds memory access, due to improper bounds checking when manipulating an array pointer. It could allow malicious users to create code execution scenarios.

Solutions

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

Adobe.Acrobat.Reader.CoolType.TTF.Memory.Corruption
Released Jul 08, 2016

Users should apply the solution provided by Adobe.

Additional Information

The vulnerability is actually triggered by a malformed font file (.ttf), embedded inside the PDF file. 

References

• https://helpx.adobe.com/security/products/acrobat/apsb16-26.html
• CVE-2016-4203

Acknowledgement

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.