The remote host is missing an update to ipsec-tools announced via advisory DSA 1804-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201804-1

Several remote vulnerabilities have been discovered in racoon, the Internet Key Exchange daemon of ipsec-tools. The The Common Vulnerabilities and Exposures project identified the following problems: Neil Kettle discovered a NULL pointer dereference on crafted fragmented packets that contain no payload. This results in the daemon crashing which can be used for denial of service attacks (CVE-2009-1574). Various memory leaks in the X.509 certificate authentication handling and the NAT-Traversal keepalive implementation can result in memory exhaustion and thus denial of service (CVE-2009-1632). For the oldstable distribution (etch), this problem has been fixed in version 0.6.6-3.1etch3. For the stable distribution (lenny), this problem has been fixed in version 0.7.1-1.3+lenny2. For the testing distribution (squeeze), this problem will be fixed soon. For the unstable distribution (sid), this problem has been fixed in version 1:0.7.1-1.5. We recommend that you upgrade your ipsec-tools packages.