CVE-2024-51775 is a vulnerability identified in Apache Zeppelin, an open-source web-based notebook for interactive data analytics. The issue stems from missing origin validation in the WebSocket connections used by Zeppelin. WebSockets are a protocol enabling full-duplex communication channels over a single TCP connection, commonly used for real-time data exchange in web applications. Proper origin validation is critical to enforce the same-origin policy, preventing unauthorized cross-origin access. In affected versions (0.11.1 up to but not including 0.12.0), Zeppelin fails to validate the 'Origin' header in WebSocket handshake requests, allowing attackers to connect from arbitrary origins. This can lead to unauthorized access to internal Zeppelin server data, specifically paragraph content, which may contain sensitive analytical results or code snippets. The vulnerability does not require any authentication or user interaction, making it remotely exploitable by any attacker with network access to the Zeppelin server. The CVSS v3.1 base score is 7.5, reflecting a high severity due to the network attack vector, low attack complexity, no privileges or user interaction required, and a high impact on confidentiality. The vulnerability is tracked under CWE-1385 (Missing Origin Validation). The Apache Software Foundation has addressed this issue in version 0.12.0 by implementing proper origin checks on WebSocket connections. No public exploits have been reported yet, but the nature of the flaw makes it a significant risk for data leakage in environments running vulnerable versions.

For European organizations, the primary impact of CVE-2024-51775 is the unauthorized disclosure of sensitive internal data within Apache Zeppelin notebooks. Zeppelin is often used in data science, analytics, and big data environments, which may contain proprietary or regulated information. Exposure of paragraph content could lead to leakage of intellectual property, business insights, or personally identifiable information (PII), potentially violating GDPR and other data protection regulations. The vulnerability does not affect data integrity or availability but compromises confidentiality. Since exploitation requires only network access and no authentication, attackers could leverage this flaw to gain insights into internal analytics workflows or prepare further attacks. Organizations in sectors such as finance, healthcare, telecommunications, and government, which rely heavily on data analytics, are at higher risk. The breach of confidentiality could result in reputational damage, regulatory penalties, and competitive disadvantage. Additionally, the vulnerability could be used as a stepping stone for more advanced attacks if combined with other weaknesses in the environment.

The most effective mitigation is to upgrade Apache Zeppelin to version 0.12.0 or later, where the missing origin validation issue is resolved. Until the upgrade can be performed, organizations should implement network-level controls to restrict access to Zeppelin servers, such as IP whitelisting, VPN enforcement, or firewall rules limiting WebSocket connections to trusted origins. Deploying Web Application Firewalls (WAFs) with custom rules to inspect and block unauthorized WebSocket handshake requests based on the Origin header can provide additional protection. Monitoring network traffic for unusual WebSocket connection attempts from unexpected origins can help detect exploitation attempts. Administrators should also review Zeppelin configurations to disable or restrict WebSocket usage if feasible. Regularly auditing Zeppelin server logs for suspicious access patterns and ensuring that Zeppelin instances are not exposed directly to the public internet without proper access controls are critical. Finally, organizations should maintain an inventory of Zeppelin deployments and ensure timely patch management aligned with security advisories.