The remote host is missing an update to pango1.0 announced via advisory DSA 1798-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201798-1

Will Drewry discovered that pango, a system for layout and rendering of internationalized text, is prone to an integer overflow via long glyphstrings. This could cause the execution of arbitrary code when displaying crafted data through an application using the pango library. For the stable distribution (lenny), this problem has been fixed in version 1.20.5-3+lenny1. For the oldstable distribution (etch), this problem has been fixed in version 1.14.8-5+etch1. For the testing distribution (squeeze) and the unstable distribution (sid), this problem has been fixed in version 1.24-1. We recommend that you upgrade your pango1.0 packages.