Zero-Day Advisory

Fortinet Discovers Multiple Stack Overflow Vulnerabilities in PHP


Two stack-based buffer overflow vulnerabilities had been discovered in PHP 5 and 7.
CVE-2016-6289 is related to core's function virtual_file_ex. The vulnerability can be triggered when PHP is handling a very long file path.
CVE-2016-6297 is related to PHP stream_zip_opener. The vulnerability can be triggered when PHP calls fopen function with an overly long filename passed to the zip:// handler.

Successful exploit of these vulnerabilities will cause memory corruption and lead to DoS. Under some conditions, remote code execution is also possible.


Users should apply the solution provided by PHP.

Additional Information

The vulnerability details can be found at


This vulnerability was discovered by Tony Loi 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.