lib32-expat: arbitrary code execution

• CVE-2015-1283 (arbitrary code execution)

Multiple integer overflows in the XML_GetBuffer function allow remote
attackers to cause a denial of service (heap-based buffer overflow) or
possibly arbitrary code execution via crafted XML data.
This problem has already been fixed in version 2.1.0-1 but this update
refreshes the fix to avoid relying on undefined behavior.

• CVE-2016-0718 (arbitrary code execution)

The Expat XML parser mishandles certain kinds of malformed input
documents, resulting in buffer overflows during processing and error
reporting. The overflows can manifest as a segmentation fault or as
memory corruption during a parse operation. The bugs allow for a denial
of service attack in many applications by an unauthenticated attacker,
and could conceivably result in remote code execution.