The remote Debian host is missing a security-related update.
Shmuel H discovered that GIMP, the GNU Image Manipulation Program, is prone to a use-after-free vulnerability in the channel and layer properties parsing process when loading a XCF file. An attacker can take advantage of this flaw to potentially execute arbitrary code with the privileges of the user running GIMP if a specially crafted XCF file is processed.
Upgrade the gimp packages. For the stable distribution (jessie), this problem has been fixed in version 2.8.14-1+deb8u1.