Improper Access Control
Mozilla Firefox before 49.0 allows remote attackers to bypass the Same Origin Policy via a crafted fragment identifier in the SRC attribute of an IFRAME element, leading to insufficient restrictions on link-color information after a document is resized.
CWE-284 - Improper Access Control
Listed 5th in the 'OWASP Top Ten', improper (or broken) access control attacks are a fundamental type of vulnerability. This includes a broad range of design flaws that enable users to act outside of their intended permissions. They can use these privileges to gain access to restricted files and functionality such as accessing restricted information, falsifying records, destroying data, or executing commands.