PHP TAR File Parsing Uninitialized Reference

July 8, 2016

A remote, unauthenticated vulnerability exists in PHP. The vulnerability allows an attacker to execute arbitrary code on the web server. CVE-2016-4343 is assigned to this vulnerability.

PHP is a server-side scripting language designed for web development but also used as a general-purpose programming language. PHP code may be embedded into HTML code, or it can be used in combination with various web template systems, web content management systems and web frameworks.

A remote code execution vulnerability exists in PHP due to lack of proper sanitation when parsing TAR files. It fails to properly validate the values inside the headers found in the file. This allows a remote attacker to create malicious TAR files to cause the vulnerable server to execute code.

The following versions of PHP are vulnerable:

  • PHP prior to 5.5.36
  • PHP prior to 5.6.22
  • PHP prior to 7.0.7

Dell SonicWALL team has written the following signature that helps protect our customers from this attack:

  • 11699: PHP phar_make_dirstream Function DoS