CVE-2023-48199 is an HTML Injection vulnerability identified in the 'manageApiKeys' component of Grocy, an open-source web-based self-hosted groceries and household management solution, affecting versions up to and including 4.0.3. The vulnerability arises because user-supplied input is not properly sanitized before being rendered in the QR code detail popup interface. Specifically, attackers can inject arbitrary HTML content into the page, although script execution (i.e., JavaScript) is not possible through this flaw. This limitation reduces the risk of direct cross-site scripting (XSS) attacks but still allows manipulation of the page's HTML structure and content. The injected HTML can be used to alter the appearance or behavior of the popup, potentially misleading users through social engineering tactics such as spoofing UI elements, displaying fraudulent messages, or tricking users into performing unintended actions. The vulnerability stems from insufficient input validation and output encoding in the affected component, which processes API key parameters. While no known exploits are currently reported in the wild, the flaw could be leveraged by attackers who have access to input fields or parameters that feed into the vulnerable component. The lack of a CVSS score indicates that the vulnerability has not yet been fully assessed for severity, but the technical details confirm that it is a published issue requiring attention.

For European organizations using Grocy for inventory or household management, this vulnerability poses a risk primarily to the integrity and trustworthiness of the user interface. Although it does not allow script execution, the ability to inject arbitrary HTML can facilitate social engineering attacks that may lead to unauthorized actions, data disclosure, or user confusion. For example, attackers could craft deceptive content in the QR code popup to trick users into revealing sensitive information or performing unsafe operations. This is particularly concerning in environments where Grocy is used in shared or multi-user settings, such as small businesses, community kitchens, or institutional facilities. The impact on confidentiality and availability is limited since no direct code execution or system compromise is enabled by this flaw. However, the manipulation of UI elements can indirectly lead to security breaches if users are deceived into unsafe behaviors. Given Grocy's open-source nature and growing adoption in Europe, organizations relying on it should be aware of this vulnerability to maintain operational security and user trust.

To mitigate this vulnerability, organizations should immediately update Grocy to a version where this issue is patched once available. In the meantime, administrators can implement strict input validation and output encoding on all user-supplied data, especially in the 'manageApiKeys' component and QR code detail popup. Employing a Content Security Policy (CSP) that restricts the execution of inline scripts and limits resource loading can reduce the risk of exploitation. Additionally, educating users about the potential for deceptive content and encouraging cautious interaction with unexpected or suspicious UI elements can help mitigate social engineering risks. Monitoring application logs for unusual input patterns or attempts to inject HTML content may also aid in early detection. If feasible, restricting access to the API key management interface to trusted users and networks will reduce the attack surface. Finally, contributing to or following updates from the Grocy community and security advisories will ensure timely application of fixes.