The remote host is missing an update to sup announced via advisory DSA 353-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20353-1

sup, a package used to maintain collections of files in identical versions across machines, fails to take appropriate security precautions when creating temporary files. A local attacker could exploit this vulnerability to overwrite arbitrary files with the privileges of the user running sup. For the stable distribution (woody) this problem has been fixed in version 1.8-8woody1. For the unstable distribution (sid) this problem has been fixed in version 1.8-9. We recommend that you update your sup package.