The remote host is missing an update to the system as announced in the referenced advisory.
The following package is affected: php5-gd
CVE-2008-5498 Array index error in the imageRotate function in PHP 5.2.8 and earlier allows context-dependent attackers to read the contents of arbitrary memory locations via a crafted value of the third argument (aka the bgd_color or clrBack argument) for an indexed image.
Solution: Update your system with the appropriate patches or software upgrades.