The remote Debian host is missing a security-related update.
Several issues have been discovered in PHP, a widely-used open source general-purpose scripting language. - CVE-2016-10158 Loading a TIFF or JPEG malicious file can lead to a Denial-of-Service attack when the EXIF header is being parsed. - CVE-2016-10159 Loading a malicious phar archive can cause an extensive memory allocation, leading to a Denial-of-Service attack on 32 bit computers. - CVE-2016-10160 An attacker might remotely execute arbitrary code using a malicious phar archive. This is the consequence of an off-by-one memory corruption. - CVE-2016-10161 An attacker with control of the unserialize() function argument can cause an out-of-bounce read. This could lead to a Denial-of-Service attack or a remote code execution.
Upgrade the php5 packages. For the stable distribution (jessie), these problems have been fixed in version 5.6.30+dfsg-0+deb8u1.