The remote host is missing an update to nasm announced via advisory DSA 623-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%20623-1

Jonathan Rockway discovered a buffer overflow in nasm, the general-purpose x86 assembler, which could lead to the execution of arbitrary code when compiling a maliciously crafted assembler source file. For the stable distribution (woody) this problem has been fixed in version 0.98.28cvs-1woody2. For the unstable distribution (sid) this problem has been fixed in version 0.98.38-1.1. We recommend that you upgrade your nasm package.