The phar_get_entry_data function in ext/phar/util.c in PHP before 5.5.30 and 5.6.x before 5.6.14 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a .phar file with a crafted TAR archive entry in which the Link indicator references a file that does not exist.<a href=https://cwe.mitre.org/data/definitions/476.html>CWE-476: NULL Pointer Dereference</a> http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-7803