The remote host is missing an update to pidgin-otr announced via advisory DSA 2476-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202476-1

intrigeri discovered a format string error in pidgin-otr, an off-the-record messaging plugin for Pidgin. This could be exploited by a remote attacker to cause arbitrary code to be executed on the user's machine. The problem is only in pidgin-otr. Other applications which use libotr are not affected. For the stable distribution (squeeze), this problem has been fixed in version 3.2.0-5+squeeze1. For the testing distribution (wheezy), this problem has been fixed in version 3.2.1-1. For the unstable distribution (sid), this problem has been fixed in version 3.2.1-1. We recommend that you upgrade your pidgin-otr packages.