Lab: Using application functionality to exploit insecure deserialization
Summary: This PortSwigger lab presents a web application that uses a serialization-based session mechanism, where a certain feature invokes a dangerous method on data supplied in a serialized object. The exercise asks the solver to edit the serialized object in the session cookie so that the avatar_link points to /home/carlos/morale.txt, update the length indicator, and use it to delete that file from Carlos's home directory.
What you should know: The exploit needs no vulnerability in the application's own code: a legitimate feature that acts on a serialized object is enough to delete a file in another user's home directory once the cookie is edited, which puts every endpoint that deserializes client-held state in scope.
Read the original at PortSwigger Research ↗
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- Vulnerabilities & Patching
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