The remote host is missing an update to apr, apr-util announced via advisory DSA 1854-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%201854-1

Matt Lewis discovered that the memory management code in the Apache Portable Runtime (APR) library does not guard against a wrap-around during size computations. This could cause the library to return a memory area which smaller than requested, resulting a heap overflow and possibly arbitrary code execution. For the old stable distribution (etch), this problem has been fixed in version 1.2.7-9 of the apr package, and version 1.2.7+dfsg-2+etch3 of the apr-util package. For the stable distribution (lenny), this problem has been fixed in version 1.2.12-5+lenny1 of the apr package and version 1.2.12-5+lenny1 of the apr-util package. For the unstable distribution (sid), this problem will be fixed soon. We recommend that you upgrade your APR packages.