webkit2gtk: multiple issues

• CVE-2016-4590 (same-origin policy bypass)

xisigr of Tencent’s Xuanwu Lab discovered a vulnerability in the way
webkit handles URLs, which allows remote attackers to bypass the Same
Origin Policy via a crafted web site.

• CVE-2016-4591 (arbitrary filesystem access)

ma.la of LINE Corporation discoveered a vulnerability in the way webkit
handles the location variable, which allows remote attackers to access
the local filesystem via unspecified vectors.

• CVE-2016-4622 (arbitrary code execution)

Samuel Gross working with Trend Micro’s Zero Day Initiative discovered a
vulnerability that allows remote attackers to execute arbitrary code or
cause a denial of service (memory corruption) via a crafted web site.

• CVE-2016-4624 (arbitrary code execution)

Apple found a vulnerability that allows remote attackers to execute
arbitrary code or cause a denial of service (memory corruption) via a
crafted web site.