The remote host is missing an update to uw-imap announced via advisory DSA 1685-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201685-1

Two vulnerabilities have been found in uw-imap, an IMAP implementation. The Common Vulnerabilities and Exposures project identifies the following problems: It was discovered that several buffer overflows can be triggered via a long folder extension argument to the tmail or dmail program. This could lead to arbitrary code execution (CVE-2008-5005). It was discovered that a NULL pointer dereference could be triggered by a malicious response to the QUIT command leading to a denial of service (CVE-2008-5006). For the stable distribution (etch), these problems have been fixed in version 2002edebian1-13.1+etch1. For the unstable distribution (sid) and the testing distribution (lenny), these problems have been fixed in version 2007d~dfsg-1. We recommend that you upgrade your uw-imap packages.