The remote host is missing an update to php4 announced via advisory DSA 1296-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201296-1

It was discovered that the ftp extension of PHP, a server-side, HTML-embedded scripting language performs insufficient input sanitising, which permits an attacker to execute arbitrary FTP commands. This requires the attacker to already have access to the FTP server. For the oldstable distribution (sarge) this problem has been fixed in version 4.3.10-21. For the stable distribution (etch) this problem has been fixed in version 4.4.4-8+etch3. For the unstable distribution (sid) this problem won't be fixed, as php4 will be removed from sid thus you are strongly advised to migrate to php5 if you prefer to follow the unstable distribution. We recommend that you upgrade your PHP packages. Packages for the Sparc