The remote host is missing an update to asterisk announced via advisory DSA 1358-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201358-1

Several remote vulnerabilities have been discovered in Asterisk, a free software PBX and telephony toolkit. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2007-1306 Mu Security discovered that a NULL pointer deference in the SIP implementation could lead to denial of service. CVE-2007-1561 Inria Lorraine discovered that a programming error in the SIP implementation could lead to denial of service. CVE-2007-2294 It was discovered that a NULL pointer deference in the manager interface could lead to denial of service. CVE-2007-2297 It was discovered that a programming error in the SIP implementation could lead to denial of service. CVE-2007-2488 Tim Panton and Birgit Arkestein discovered that a programming error in the IAX2 implementation could lead to information disclosure. CVE-2007-3762 Russell Bryant discovered that a buffer overflow in the IAX implementation could lead to the execution of arbitrary code. CVE-2007-3763 Chris Clark and Zane Lackey discovered that several NULL pointer deferences in the IAX2 implementation could lead to denial of service. CVE-2007-3764 Will Drewry discovered that a programming error in the Skinny implementation could lead to denial of service. For the oldstable distribution (sarge) these problems have been fixed in version 1.0.7.dfsg.1-2sarge5. For the stable distribution (etch) these problems have been fixed in version 1:1.2.13~dfsg-2etch1. For the unstable distribution (sid) these problems have been fixed in version 1:1.4.11~dfsg-1. We recommend that you upgrade your Asterisk packages.