CVE-2026-106677 in homestay-backend
Summary
by MITRE • 10/26/2026
Homestay3 homestay-backend 0.0.1-SNAPSHOT contains an IDOR in ChatServiceImpl. An authenticated user can view conversations, read messages, send messages, and mark messages as read for arbitrary conversation ids because the service does not verify that the caller is a conversation participant.
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Analysis
by VulDB Data Team • 10/26/2026
The vulnerability identified within Homestay3 homestay-backend version 0.0.1-SNAPSHOT represents a classic Insecure Direct Object Reference (IDOR) flaw located specifically in the ChatServiceImpl component of the application backend. This security defect stems from a fundamental failure in access control logic, where the system processes requests based on user-supplied input without adequately validating whether that input is authorized for the current authenticated session. Specifically, the service allows an attacker who has successfully authenticated to interact with chat conversations by providing arbitrary conversation identifiers. The core technical flaw lies in the absence of ownership verification or participant validation checks before executing operations such as viewing conversation history, reading individual messages, sending new messages, or marking existing messages as read. Because the application trusts the client-provided identifier without cross-referencing it against a database record that maps users to their authorized conversations, any authenticated user can bypass intended privacy boundaries and access data belonging to other users.
From an operational perspective, this vulnerability poses significant risks to both confidentiality and integrity of user communications. The ability to view conversations and read messages for arbitrary conversation IDs allows attackers to perform unauthorized surveillance on private discussions between other parties. This exposure violates the principle of least privilege and compromises the expectation of privacy inherent in messaging applications. Furthermore, the capability to send messages under another user's context or manipulate message states can lead to social engineering attacks, reputation damage, or disruption of services by injecting malicious content into legitimate conversations. The lack of verification means that the application fails to enforce proper authorization controls at the business logic layer, treating all authenticated users as having equal access rights regardless their actual relationship with the target resource.
This vulnerability aligns directly with CWE-639, which is categorized under Insecure Direct Object Reference in the Common Weakness Enumeration standard. It also maps closely to MITRE ATT&CK technique T1078, specifically Valid Accounts, as it exploits legitimate credentials to access resources that are not intended for those accounts. The attack vector typically involves a simple HTTP request where the attacker modifies the conversation ID parameter sent to the backend API endpoint responsible for chat operations. Since no server-side check confirms if the requesting user is listed in the participants table or has permission associated with that specific conversation UUID, the system blindly executes the requested action.
To mitigate this vulnerability, developers must implement robust authorization checks within the ChatServiceImpl class before processing any request related to a specific conversation ID. The application should query the database to verify that the authenticated user's identifier exists in the list of participants for the targeted conversation ID. If the verification fails, the system must immediately reject the request with an appropriate HTTP 403 Forbidden status code rather than proceeding with data retrieval or modification operations. Additionally, implementing a centralized access control service can help ensure consistent enforcement across all endpoints that handle sensitive resources. Regular security testing and static application security scanning should be integrated into the development lifecycle to detect such logic flaws early in the software development process.