CVE-2024-42468: 
Java vulnerability analysis and mitigation

CometVisuServlet in versions prior to 4.2.1 is susceptible to an unauthenticated path traversal vulnerability in openHAB, a provider of open-source home automation software. Local files on the server can be requested via HTTP GET on the CometVisuServlet, which may lead to information disclosure. The vulnerability was discovered in August 2024 and affects the visualization add-on CometVisu (NVD, GitHub Advisory).

The vulnerability stems from insufficient path validation in the CometVisuServlet's file handling mechanism. The issue occurs in the getRequestedFile method where URL decoding is performed without proper path validation, allowing for directory traversal. The vulnerability has been assigned a CVSS v3.1 base score of 7.5 HIGH (Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N) by NIST NVD, while GitHub assessed it as 5.3 MEDIUM (Security Lab).

The vulnerability allows attackers to access local files on the server through path traversal, potentially leading to sensitive information disclosure. An attacker can exploit this vulnerability to read arbitrary files accessible to the application process (Security Lab).

The vulnerability can be exploited without authentication via HTTP GET requests to the CometVisuServlet. A proof of concept demonstrates that an attacker can access sensitive files like /etc/passwd by using URL double encoding of path traversal sequences (Security Lab).

Users should upgrade to version 4.2.1 of the CometVisu add-on of openHAB to receive the security patch. The vulnerability has been fixed by implementing proper path validation (GitHub Advisory, NVD).