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having Difficulties in solving lab

Nikhil | Last updated: Jul 09, 2020 03:28PM UTC

i am trying to solve this lab Lab: Developing a custom gadget chain for Java deserialization . When i am trying to serialise java cookie i am using your githup main.java in repl.it but i am getting an error Input:- import data.productcatalog.ProductTemplate; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.util.Base64; class Main { public static void main(String[] args) throws Exception { ProductTemplate originalObject = new ProductTemplate("id=1'"); String serializedObject = serialize(originalObject); System.out.println("Serialized object: " + serializedObject); ProductTemplate deserializedObject = deserialize(serializedObject); System.out.println("Deserialized object ID: " + deserializedObject.getId()); } private static String serialize(Serializable obj) throws Exception { ByteArrayOutputStream baos = new ByteArrayOutputStream(512); try (ObjectOutputStream out = new ObjectOutputStream(baos)) { out.writeObject(obj); } return Base64.getEncoder().encodeToString(baos.toByteArray()); } private static <T> T deserialize(String base64SerializedObj) throws Exception { try (ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(Base64.getDecoder().decode(base64SerializedObj)))) { @SuppressWarnings("unchecked") T obj = (T) in.readObject(); return obj; } } } Output:- import data.productcatalog.ProductTemplate; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.util.Base64; class Main { public static void main(String[] args) throws Exception { ProductTemplate originalObject = new ProductTemplate("id=1'"); String serializedObject = serialize(originalObject); System.out.println("Serialized object: " + serializedObject); ProductTemplate deserializedObject = deserialize(serializedObject); System.out.println("Deserialized object ID: " + deserializedObject.getId()); } private static String serialize(Serializable obj) throws Exception { ByteArrayOutputStream baos = new ByteArrayOutputStream(512); try (ObjectOutputStream out = new ObjectOutputStream(baos)) { out.writeObject(obj); } return Base64.getEncoder().encodeToString(baos.toByteArray()); } private static <T> T deserialize(String base64SerializedObj) throws Exception { try (ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(Base64.getDecoder().decode(base64SerializedObj)))) { @SuppressWarnings("unchecked") T obj = (T) in.readObject(); return obj; } } } What should be done to solve this ? I am stuck here. Please CLarify my Doubt

Hannah, PortSwigger Agent | Last updated: Jul 10, 2020 08:57AM UTC

Hi. I have input the serialization-examples-master/java/solution folder contents into repl.it, and changed the "new ProductTemplate" to match your "id=1" and have not got the same output as you. Instead, I got the following output: > javac -classpath .:/run_dir/junit-4.12.jar:target/dependency/* -d . Main.java data/productcatalog/Product.java data/productcatalog/ProductTemplate.java > java -classpath .:/run_dir/junit-4.12.jar:target/dependency/* Main Serialized object: rO0ABXNyACNkYXRhLnByb2R1Y3RjYXRhbG9nLlByb2R1Y3RUZW1wbGF0ZQAAAAAAAAABAgABTAACaWR0ABJMamF2YS9sYW5nL1N0cmluZzt4cHQABGlkPTE= Deserialized object ID: id=1 >

Nikhil | Last updated: Jul 10, 2020 10:20AM UTC

can you send me what is your code with id=1 Because i am getting smae error with id=1

Hannah, PortSwigger Agent | Last updated: Jul 10, 2020 10:29AM UTC

Here is the link to the repl.it program: https://repl.it/repls/FreshClearcutPresses#Main.java All I've done is copy the contents of the solution folder into it, and changed "your-payload-here" to "id=1" and run the program.

Nikhil | Last updated: Jul 10, 2020 10:53AM UTC

yeah it worked thanks hannah for helping me out

mouft | Last updated: Dec 01, 2020 04:03AM UTC

hi hope u doing well so i have this probleme can somone explain to me plz  javac -classpath .:/run_dir/junit-4.12.jar:target/dependency/* -d . Main.java Main.java:1: error: package data.productcatalog does not exist import data.productcatalog.ProductTemplate; ^ Main.java:11: error: cannot find symbol ProductTemplate originalObject = new ProductTemplate("id=1"); ^ symbol: class ProductTemplate location: class Main Main.java:11: error: cannot find symbol ProductTemplate originalObject = new ProductTemplate("id=1"); ^ symbol: class ProductTemplate location: class Main Main.java:17: error: cannot find symbol ProductTemplate deserializedObject = deserialize(serializedObject); ^ symbol: class ProductTemplate location: class Main 4 errors

Hannah, PortSwigger Agent | Last updated: Dec 01, 2020 09:03AM UTC

Hi Have you included the data folder in your download and compile? It looks like your errors are saying that it hasn't been included.

mouft | Last updated: Dec 01, 2020 09:46PM UTC

OMG im an idiot , thank you so much !

uniform | Last updated: Jan 08, 2021 09:01PM UTC

Hi Everyone, Not sure what's going on but I'm getting the following error 'org.apache.commons.lang3.SerializationException: java.lang.ClassNotFoundException: ProductTemplate' Aren't we expected to create and object of type ProductTemplate to solve the lab? Let me know what do you think about it. Thanks.

uniform | Last updated: Jan 08, 2021 09:03PM UTC

To clarify for the post above, I was able to successfully create the object on client side and received the error from the application after it must have deserialized.

Hannah, PortSwigger Agent | Last updated: Jan 11, 2021 01:20PM UTC

Have you tried following along with a video solution instead of the written one? This is a good example: https://youtu.be/uqPrrzydKdg

Gian | Last updated: Jan 11, 2024 10:37PM UTC

Buenas! como andan? tengo el mismo problema: java.lang.ClassNotFoundException: data.ProductTemplate. nose que hacer, actualize el java en mi SO, mediante el binario, tambien el comando update-alternatives, en la terminal me devuelve bien el objeto serializado y en el IDE también, el tema es cuando pongo el payload en la cookie me devuelve la excepción antes mencionada: java.lang.ClassNotFoundException: data.ProductTemplate. Alguien me podría ayudar con esto por favor? estuve atascado un par de horas

Hannah, PortSwigger Agent | Last updated: Jan 15, 2024 11:40AM UTC

Hi

It seems like you're not compiling the code correctly.

Have you included the "data/productcatalog" directory?

If not, you could provide the classes after the Main class.

This would look like this at the bottom of Main.java:
class Product {}

class ProductTemplate implements Serializable
{
    static final long serialVersionUID = 1L;

    private final String id;
    private transient Product product;

    public ProductTemplate(String id)
    {
        this.id = id;
    }

    public String getId() {
        return id;
    }
}

Gregory | Last updated: Mar 06, 2024 04:50PM UTC

replacing the cookie with my payload am getting the following response <h4>Internal Server Error</h4> <p class=is-warning>java.lang.ClassNotFoundException: main.ProductTemplate</p> </div>

Hannah, PortSwigger Agent | Last updated: Mar 07, 2024 11:55AM UTC

Hi If you've not compiled the code correctly, with all included packages, the additional classes will not be included in your resulting JAR file. If you find it easier, you can include the classes contained in different files at the bottom of Main instead - there's an example of what to add to the bottom of your Main file above.

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