The remote host is missing an update to asterisk announced via advisory DSA 2550-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202550-1

Several vulnerabilities were discovered in Asterisk, a PBX and telephony toolkit, allowing privilege escalation in the Asterisk Manager, denial of service or privilege escalation. More detailed information can be found in the Asterisk advisories: http://downloads.asterisk.org/pub/security/AST-2012-010.html http://downloads.asterisk.org/pub/security/AST-2012-011.html http://downloads.asterisk.org/pub/security/AST-2012-012.html http://downloads.asterisk.org/pub/security/AST-2012-013.html For the stable distribution (squeeze), these problems have been fixed in version 1:1.6.2.9-2+squeeze7. For the testing distribution (wheezy) and the unstable distribution (sid), these problems have been fixed in version 1:1.8.13.1~dfsg-1. We recommend that you upgrade your asterisk packages.