LibreChat, an enhanced ChatGPT clone supporting multiple AI providers, contains an IDOR vulnerability (CWE-862) in its API keys management endpoint (PUT /api/keys) in versions up to 0.7.6. The flaw arises from the use of the JavaScript object spread operator after setting the authenticated user's ID, allowing an authenticated user to inject a userId parameter in the request body. This enables overwriting of any other user's API key configurations, potentially redirecting victim conversations through attacker-controlled keys or causing denial of service by invalidating keys. The vulnerability has a CVSS 3.1 score of 7.1 (high severity) with network attack vector, low attack complexity, requiring privileges and no user interaction. It is patched in version 0.8.3-rc1. As LibreChat is a cloud service, the vendor manages remediation server-side.

An attacker with authenticated access can manipulate other users' API key configurations, which may allow them to intercept or alter AI conversation data by routing it through attacker-controlled keys or disrupt service by setting invalid keys. There is no direct confidentiality impact reported, but integrity and availability impacts are high. No known exploits in the wild have been reported.

A patch is available in LibreChat version 0.8.3-rc1 that fixes this vulnerability. Since LibreChat is a cloud-hosted service, the vendor manages remediation server-side. Users should ensure they are using version 0.8.3-rc1 or later. Patch status is confirmed by the vendor advisory. No additional mitigation actions are specified.