The remote host is missing an update to imlib2 announced via advisory DSA 2029-1.

https://secure1.securityspace.com/smysecure/catid.html?in=DSA%202029-1

It was discovered that imlib2, a library to load and process several image formats, did not properly process various image file types. Several heap and stack based buffer overflows - partly due to integer overflows - in the ARGB, BMP, JPEG, LBM, PNM, TGA and XPM loaders can lead to the execution of arbitrary code via crafted image files. For the stable distribution (lenny), this problem has been fixed in version 1.4.0-1.2+lenny1. For the testing distribution (squeeze), this problem has been fixed in version 1.4.2-1. For the unstable distribution (sid), this problem has been fixed in version 1.4.2-1.