The remote host is missing an update to icedove announced via advisory DSA 1391-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201391-1

Several remote vulnerabilities have been discovered in the Icedove mail client, an unbranded version of the Thunderbird client. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2007-3734 Bernd Mielke, Boris Zbarsky, David Baron, Daniel Veditz, Jesse Ruderman, Lukas Loehrer, Martijn Wargers, Mats Palmgren, Olli Pettay, Paul Nickerson and Vladimir Sukhoy discovered crashes in the layout engine, which might allow the execution of arbitrary code. CVE-2007-3735 Asaf Romano, Jesse Ruderman and Igor Bukanov discovered crashes in the javascript engine, which might allow the execution of arbitrary code. CVE-2007-3844 moz_bug_r_a4 discovered that a regression in the handling of about:blank windows used by addons may lead to an attacker being able to modify the content of web sites. CVE-2007-3845 Jesper Johansson discovered that missing sanitising of double-quotes and spaces in URIs passed to external programs may allow an attacker to pass arbitrary arguments to the helper program if the user is tricked into opening a malformed web page. CVE-2007-5339 L. David Baron, Boris Zbarsky, Georgi Guninski, Paul Nickerson, Olli Pettay, Jesse Ruderman, Vladimir Sukhoy, Daniel Veditz, and Martijn Wargers discovered crashes in the layout engine, which might allow the execution of arbitrary code. CVE-2007-5340 Igor Bukanov, Eli Friedman, and Jesse Ruderman discovered crashes in the Javascript engine, which might allow the execution of arbitrary code. Generally, enabling Javascript in Icedove is not recommended. The Mozilla products in the oldstable distribution (sarge) are no longer supported with security updates. For the stable distribution (etch) these problems have been fixed in version 1.5.0.13+1.5.0.14b.dfsg1-0etch1. Builds for hppa will be provided later. The unstable distribution (sid) will be fixed soon. We recommend that you upgrade your icedove packages.