meaning of "a user's browser" in Microsoft Security Update description

Question

I have a bunch of Security Updates in queue for Windows 7, affecting various versions of the .NET framework. I read some of the descriptions. Here's one:

This update resolves vulnerabilities in the Microsoft .NET Framework. The most severe of these vulnerabilities could allow elevation of privilege if an attacker injects a client-side script into a user's browser. To learn more about this vulnerability, see Microsoft Security Bulletin MS15-118.

Security Bulletin MS15-118 says:

The most severe of the vulnerabilities could allow elevation of privilege if an attacker convinces a user to navigate to a compromised website or open a link in a specially crafted email that is designed to inject client-side code into the user’s browser.

What is meant by "user's browser" in this context? Does this vulnerability affect any browser, not just IE?

Answer 1

There are many browsers that are simply a skin on top of another browser and WebKit isn't the only engine that has a million browsers using the same engine.

There was also a good few extensions that could allow you to run IE in a Firefox tab.

In this context it is quite likely that they do mean IE, but are also including any "browser" that can make use of the IE engine or even hand off to .NET via an add-on or extension.

For security purposes you should assume that any browser could hand out to the compromised modules that are being patched.