CVE-2024-31860 is a path traversal vulnerability (CWE-22) affecting Apache Zeppelin versions from 0.9.0 up to but not including 0.11.0. Apache Zeppelin is an open-source web-based notebook that enables interactive data analytics and visualization, widely used in data science and big data environments. The vulnerability arises due to improper input validation of file path parameters. Specifically, an attacker can supply relative path indicators such as ".." in file path inputs, allowing traversal outside the intended restricted directories. This enables the attacker to access arbitrary files on the server filesystem that the Apache Zeppelin server process has permission to read. The vulnerability does not require user interaction but does require the attacker to have some level of privileges (PR:L - privileges required: low). The CVSS 3.1 base score is 6.5 (medium severity), with a vector indicating network attack vector (AV:N), low attack complexity (AC:L), privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and no availability impact (A:N). This means an attacker with low privileges can remotely exploit the vulnerability to read sensitive files, potentially exposing confidential information such as configuration files, credentials, or other sensitive data stored on the server. The issue was fixed in Apache Zeppelin version 0.11.0, and users are strongly recommended to upgrade to this version or later to mitigate the risk. No known exploits are reported in the wild as of the publication date (April 9, 2024).

For European organizations, the impact of this vulnerability can be significant, especially for those relying on Apache Zeppelin for data analytics, business intelligence, or research purposes. Unauthorized file access can lead to exposure of sensitive corporate data, intellectual property, or personally identifiable information (PII), potentially violating GDPR and other data protection regulations. The confidentiality breach could also facilitate further attacks, such as credential theft or lateral movement within the network. Since Apache Zeppelin is often deployed in enterprise environments handling critical data workflows, exploitation could disrupt data integrity indirectly by exposing sensitive information to unauthorized parties. The medium severity rating reflects that while the vulnerability does not allow code execution or direct system compromise, the confidentiality impact is high, and the ease of exploitation is relatively low due to the low privilege requirement and network accessibility. Organizations in sectors such as finance, healthcare, research institutions, and government agencies in Europe could face reputational damage, regulatory penalties, and operational risks if this vulnerability is exploited.

1. Immediate upgrade of Apache Zeppelin installations to version 0.11.0 or later, where the vulnerability is patched, is the most effective mitigation. 2. Restrict network access to Apache Zeppelin servers to trusted internal networks or VPNs to reduce exposure to external attackers. 3. Implement strict access controls and least privilege principles for Zeppelin server accounts to minimize the filesystem access scope. 4. Employ web application firewalls (WAFs) with custom rules to detect and block path traversal attempts, such as requests containing ".." sequences in file path parameters. 5. Conduct regular security audits and code reviews of custom Zeppelin notebooks or integrations that may interact with file paths to ensure no unsafe input handling. 6. Monitor logs for suspicious access patterns or anomalous file access requests indicative of exploitation attempts. 7. Educate administrators and users about the risks of running outdated Zeppelin versions and the importance of timely patching. 8. If upgrading is not immediately feasible, consider deploying temporary compensating controls such as containerization or sandboxing to isolate Zeppelin processes and limit filesystem exposure.