The remote host is missing an update to sox announced via advisory DSA 565-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20565-1

Ulf Harnhammar has reported two vulnerabilities in SoX, a universal sound sample translator, which may be exploited by malicious people to compromise a user's system with a specially crafted .wav file. For the stable distribution (woody) these problems have been fixed in version 12.17.3-4woody2. For the unstable distribution (sid) these problems have been fixed in version 12.17.4-9. We recommend that you upgrade your sox package.