A mass assignment vulnerability exists in the /api/invite/:code endpoint of the mintplex-labs/anything-llm repository, allowing unauthorized creation of high-privileged accounts. By intercepting and modifying the HTTP request during the account creation process via an invitation link, an attacker can add a role property with admin value, thereby gaining administrative access. This issue arises due to the lack of property allowlisting and blocklisting, enabling the attacker to exploit the system and perform actions as an administrator.
The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.
If the object contains attributes that were only intended for internal use, then their unexpected modification could lead to a vulnerability. This weakness is sometimes known by the language-specific mechanisms that make it possible, such as mass assignment, autobinding, or object injection.