expat - security update

Gustavo Grieco discovered that Expat, an XML parsing C library, does not
properly handle certain kinds of malformed input documents, resulting in
buffer overflows during processing and error reporting. A remote
attacker can take advantage of this flaw to cause an application using
the Expat library to crash, or potentially, to execute arbitrary code
with the privileges of the user running the application.

For the stable distribution (jessie), this problem has been fixed in
version 2.1.0-6+deb8u2. Additionally this update refreshes the fix for
CVE-2015-1283 to avoid relying on undefined behavior.

We recommend that you upgrade your expat packages.