The remote host is missing an update to icedove announced via advisory DSA 2464-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202464-1

Several vulnerabilities have been discovered in Icedove, an unbranded version of the Thunderbird mail/news client. CVE-2012-0467 Bob Clary, Christian Holler, Brian Hackett, Bobby Holley, Gary Kwong, Hilary Hall, Honza Bambas, Jesse Ruderman, Julian Seward, and Olli Pettay discovered memory corruption bugs, which may lead to the execution of arbitrary code. CVE-2012-0470 Atte Kettunen discovered that a memory corruption bug in gfxImageSurface may lead to the execution of arbitrary code. CVE-2012-0471 Anne van Kesteren discovered that incorrect multibyte octet decoding may lead to cross-site scripting. CVE-2012-0477 Masato Kinugawa discovered that incorrect encoding of Korean and Chinese character sets may lead to cross-site scripting. CVE-2012-0479 Jeroen van der Gun discovered a spoofing vulnerability in the presentation of Atom and RSS feeds over HTTPS. For the stable distribution (squeeze), this problem has been fixed in version 3.0.11-1+squeeze9. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your icedove packages.