IIS
Internet Information Services
Microsoft's web server, built into Windows Server.
Where It Sits
The small stack marks its layer. Beside it, each related technology links to its own page.
- App
- Framework
- Web ServerIIS
- Runtime
- Containers
- OS
- Hypervisor
- Firmware
- Hardware
- Data
About
IIS takes web requests and runs the application that answers them in its own worker processes, usually an ASP.NET one such as SharePoint or Exchange. It can also run PHP sites through FastCGI, a standard way for a web server to hand each request to another program. IIS then starts and recycles the PHP processes itself. It runs only on Windows, usually Windows Server.
How to Spot It
These are signs that a system runs IIS, seen from outside without signing in, such as a response header, a cookie, a path or a default port. They help you find where it runs across your own estate. A version shown to the world also tells anyone scanning which flaws might apply, so it is worth hiding.
- Response header
Server: Microsoft-IIS/10.0- Response header (an IIS default)
X-Powered-By: ASP.NET- Cookie
ASP.NET_SessionId
If It Has a Flaw
A flaw in IIS or in the Windows HTTP stack under it can expose every site it runs, SharePoint, Exchange and any PHP site included.
A flaw exposes what runs on it and the data it reaches.
- Application
SharePoint
Exchange ServerMOVEit Transfer- Framework and Libraries
- ASP.NET
- Data
SQL Server
Rivals
Rivals do the same job on the same layer, so a system usually runs one of them in any one place. A flaw in a rival does not reach IIS.
Stacks and Code
IIS is part of the common stacks below, and each stack's page shows who runs every layer. Its code arrives from the sources listed, and each source's page says how bad code could get in through it.
- In Common Stacks
- SharePoint, On PremisesExchange, On Premises
- Its Code Comes From
- Vendor Updates