Dan Kaminsky and Moxie Marlinspike discovered that kdelibs, core libraries from the official KDE release, does not properly handle a "\0" character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority. For the oldstable distribution , this problem has been fixed in version 4:3.5.5a.dfsg.1-8etch3 Due to a bug in the archive system, the fix for the stable distribution , will be released as version 4:3.5.10.dfsg.1-0lenny3 once it is available. For the testing distribution , and the unstable distribution , this problem has been fixed in version 4:3.5.10.dfsg.1-2.1 We recommend that you upgrade your kdelibs pakcages.