CVE-2024-11171 is a vulnerability identified in the danny-avila/librechat project, specifically related to the use of the multer middleware for handling multipart file uploads. Multer's default configuration uses in-memory storage without imposing any limits on the size of uploaded files. This lack of input validation and resource control allows an unauthenticated attacker to send arbitrarily large files, which are fully loaded into server memory. As a result, the server can experience out-of-memory conditions leading to crashes and a complete denial of service (DoS). The vulnerability is classified under CWE-770, which concerns allocation of resources without limits or throttling. The CVSS v3.0 score of 7.5 reflects a high severity, with network attack vector, no privileges or user interaction needed, and impact limited to availability (no confidentiality or integrity impact). The vulnerability affects unspecified versions prior to 0.7.6, where the issue has been fixed. No known exploits are reported in the wild yet, but the ease of exploitation and potential impact make it a significant risk for deployments of librechat using vulnerable versions.

For European organizations using danny-avila/librechat, this vulnerability poses a significant risk of service disruption due to denial of service attacks. The inability to limit file upload sizes can lead to server crashes, causing downtime and potential loss of availability for chat services. This can affect internal communications, customer support channels, or any business processes relying on librechat. The lack of confidentiality or integrity impact means data theft or manipulation is not a direct concern, but availability loss can have cascading effects on operational continuity and reputation. Organizations in sectors with high dependency on real-time communication platforms, such as finance, healthcare, and government, may face amplified consequences. Additionally, the vulnerability can be exploited remotely without authentication, increasing the attack surface and risk exposure.

European organizations should immediately upgrade danny-avila/librechat to version 0.7.6 or later where the vulnerability is fixed. Until upgrade is possible, implement strict file size limits on uploads at the web server or reverse proxy level to prevent large payloads from reaching the application. Configure multer or any file upload middleware to use disk storage with enforced size limits rather than in-memory storage. Employ rate limiting and request throttling to reduce the risk of resource exhaustion attacks. Monitor server memory usage and set up alerts for abnormal spikes that could indicate exploitation attempts. Conduct regular security audits of third-party dependencies and middleware configurations to ensure secure defaults. Finally, consider deploying web application firewalls (WAFs) with rules to detect and block suspicious multipart upload patterns.