The remote host is missing an update to ruby announced via advisory DSA 860-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20860-1

Yutaka Oiwa discovered a bug in Ruby, the interpreter for the object-oriented scripting language, that can cause illegal program code to bypass the safe level and taint flag protections check and be executed. The following matrix lists the fixed versions in our distributions: old stable (woody) stable (sarge) unstable (sid) ruby 1.6.7-3woody5 n/a n/a ruby1.6 n/a 1.6.8-12sarge1 1.6.8-13 ruby1.8 n/a 1.8.2-7sarge2 1.8.3-1 We recommend that you upgrade your ruby packages.