All-in-one plugin for Burp Suite for the detection and the exploitation of Java deserialization vulnerabilities
Java Deserialization Scanner is a Burp Suite plugin aimed at detect and exploit Java deserialization vulnerabilities. It was written by Federico Dotta, a Security Advisor at @ Mediaservice.net.
The plugin is made up of three different components:
A brief article containing a mini walkthrough on how to use the various components of the plugin can be found at the following URL: https://techblog.mediaservice.net/2017/05/reliable-discovery-and-exploitation-of-java-deserialization-vulnerabilities/
Java Deserialization Scanner uses custom payloads generated with a modified version of "ysoserial", tool created by frohoff and gebl, to detect Java deserialization vulnerabilities. The original tool (https://github.com/frohoff/ysoserial) generate payloads for the execution of commands on the system, using the Runtime.exec function. Usually, however, it is not possible to see the output of the command and consequently it is not simple to write a scanner based on this kind of function. For this reason, a modified version of ysoserial is used to generate different types of payloads, usefull for the detection of the issue instead of the exploitation:
Currently, the passive checks of the Java Deserialiation Scanner reported the presence of serialized Java objects in the HTTP requests and the active checks actively scan for the presence of weak deserialization functions in conjuction with the presence of the following weak libraries:
Furthermore, URLSNDS payload has been introduced to actively detect Java deserialization without any vulnerable libraris. If the plugin find only the URLDNS issue (and no vulnerable libraries), the attacker probably can execute DoS attacks but to achieve Remote Code Execution it is necessary more effort. Refer to this link for more details.
All the components of the plugin supports the following encodings:
In the test folder there are some simple Java server applications that can be used to test the plugin. Every application employ a different vulnerable Java library.
The plugin offer a dedicated tab to launch the detection with the sleep and DNS payloads on custom insertion points, in order to check the Java deserialization vulnerabilities in particular situations in which strange entry points do not allow the detection with the scanner. The results of the manual tester can be inserted between Burp Suite scanner results.
The manual tester offers an extra detection method: CPU detection. The CPU detection method is based on Wouter Coekaerts’ SerialDOS work (https://gist.github.com/coekie/a27cc406fc9f3dc7a70d) and it is able to detect deserialization issues without the presence of any vulnerable library, using an object that employs many CPU cycles for the deserialization task and checking the time of the response. The CPU detection method is not included by default in the active scan checks, because it must be used with caution: sending a huge number of “light” SerialDOS payloads may still cause problems on old or highly-loaded systems.
After that a Java deserialization vulnerability has been found, it is possible to actively exploit the issue with the Exploiting dedicated tab. The “Exploiting” tab offers a comfortable interface to exploit deserialization vulnerabilities. This tab uses the ysoserial tool to generate exploitation vectors and includes the generated payload in a HTTP request. ysoserial takes as argument a vulnerable library and a command and generates a serialized object in binary form that can be sent to the vulnerable application to execute the command on the target system (obviously if the target application is vulnerable). The Exploiting tab supports the same encoding formats as the detection sections of the plugin.
In order to improve this extension, please report any issue founded in the plugin. Furthermore if you want report me any disclosed Java library usefull for the exploitation of this weakness and, if I have the time, I will add an active check for it in my plugin.
This software has been created purely for the purposes of academic research and for the development of effective defensive techniques, and is not intended to be used to attack systems except where explicitly authorized. Project maintainers are not responsible or liable for misuse of the software. Use responsibly.
Copyright (c) 2020 Java Deserialization Scanner
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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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