Code Access Security

<p>Code Access Security (CAS), in the <a href="/facts/Microsoft_.NET/Hh5tWDIw">Microsoft .NET</a> framework, is <a href="/facts/Microsoft/nGIDDXdx">Microsoft</a>'s solution to prevent untrusted code from performing privileged actions. When the <a href="/facts/Common_Language_Runtime/4Y0cUdkd">CLR</a> loads an <a href="/facts/Assembly_(CLI)/F4EGfYsU">assembly</a> it will obtain evidence for the assembly and use this to identify the code group that the assembly belongs to. A code group contains a permission set (one or more <a href="/facts/File_system_permissions/DHq5SwI4">permissions</a>). Code that performs a privileged action will perform a code access demand which will cause the CLR to walk up the <a href="/facts/Call_stack/1sMt713v">call stack</a> and examine the permission set granted to the assembly of each <a href="/facts/Method_(computer_science)/8kAXxVYs">method</a> in the call stack. 
The code groups and permission sets are determined by the administrator of the machine who defines the security policy. 
Microsoft considers CAS as obsolete and discourages its use. It is also not available in .NET Core and .NET.
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Code Access Security open-in-new

Code Access Security