The remote host is missing an update to evolution announced via advisory DSA 1512-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201512-1

Ulf Härnhammar discovered that Evolution, the e-mail and groupware suite, had a format string vulnerability in the parsing of encrypted mail messages. If the user opened a specially crafted email message, code execution was possible. For the stable distribution (etch), this problem has been fixed in version 2.6.3-6etch2. For the old stable distribution (sarge), this problem has been fixed in version 2.0.4-2sarge3. Some architectures have not yet completed building the updated package for sarge at this time, they will be added as they come available. For the unstable distribution (sid), this problem has been fixed in version 2.12.3-1.1. We recommend that you upgrade your evolution package.