Improper Input Validation in mintplex-labs/anything-llm

Vulnerability Description

In mintplex-labs/anything-llm, an attacker can exploit improper input validation by sending a malformed JSON payload to the '/system/enable-multi-user' endpoint. This triggers an error that is caught by a catch block, which in turn deletes all users and disables the 'multi_user_mode'. The vulnerability allows an attacker to remove all existing users and potentially create a new admin user without requiring a password, leading to unauthorized access and control over the application.

References

• https://huntr.com/bounties/7189a7a0-9830-459d-b853-bdc2559999a0
• https://github.com/mintplex-labs/anything-llm/commit/99cfee1e7025fe9a0919a4d506ba1e1b819f6073