Jooby is a web framework for Java and Kotlin. The pac4j io.jooby.internal.pac4j.SessionStoreImpl#get module deserializes untrusted data. This vulnerability is fixed in 2.17.0 (2.x) and 3.7.0 (3.x).

Affected: Maven: io.jooby:jooby-pac4j

### Impact

Versions after 2.x and before 3.x of io.jooby:jooby-pac4j can cause deserialization of untrusted data

### Patches

- 2.17.0 (2.x) - 3.7.0 (3.x)

### Workarounds

- Not using io.jooby:jooby-pac4j until it gets patches. - Check what values you put/save on session

### References

Version 2.x:

https://github.com/jooby-project/jooby/blob/v2.x/modules/jooby-pac4j/src/main/java/io/jooby/internal/pac4j/SessionStoreImpl.java#L39-L45

Version 3.x: https://github.com/jooby-project/jooby/blob/v3.6.1/modules/jooby-pac4j/src/main/java/io/jooby/internal/pac4j/SessionStoreImpl.java#L77-L84

### Cause

In module pac4j io.jooby.internal.pac4j.SessionStoreImpl#get , it is used to handle sessions , and trying to get key value. In strToObject function ,it's trying to deserialize value when value starts with "b64~" , which might cause deserialization of untrusted data.

[modules/jooby-pac4j/src/main/java/io/jooby/internal/pac4j/SessionStoreImpl.java](https://github.com/jooby-project/jooby/blob/v3.6.1/modules/jooby-pac4j/src/main/java/io/jooby/internal/pac4j/SessionStoreImpl.java#L77-L84)

Here's a small demo using SessionStoreImpl#get to handle sessions ,and user can pass parameters.


And following below is exploiting successfully(execute calculator)