The remote host is missing an update to pulseaudio announced via advisory DSA 1838-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201838-1

Tavis Ormandy and Julien Tinnes discovered that the pulseaudio daemon does not drop privileges before re-executing itself, enabling local attackers to increase their privileges. The old stable distribution (etch) is not affected by this issue. For the stable distribution (lenny), this problem has been fixed in version 0.9.10-3+lenny1. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your pulseaudio packages.