CVE-2024-48531 is a reflected cross-site scripting (XSS) vulnerability identified in the Rental Availability module of eSoft Planner version 3.24.08271-USA. Reflected XSS occurs when user-supplied input is immediately returned by a web application without proper sanitization or encoding, allowing attackers to inject malicious JavaScript code. In this case, the vulnerability enables attackers to craft URLs or input payloads that, when accessed by authenticated users, execute arbitrary scripts within their browser context. This can lead to session hijacking, credential theft, or unauthorized actions performed with the victim's privileges. The vulnerability requires network access (AV:N), low attack complexity (AC:L), and privileges (PR:L), meaning the attacker must have some level of authenticated access, and user interaction (UI:R) is necessary for exploitation. The scope is changed (S:C), indicating that the vulnerability affects resources beyond the vulnerable component, potentially impacting the entire application or user session. The CVSS vector reflects limited confidentiality and integrity impacts (C:L/I:L) but no availability impact (A:N). No patches or known exploits are currently available, highlighting the importance of proactive mitigation. The vulnerability is classified under CWE-79, a common weakness related to improper neutralization of input during web page generation.

The primary impact of CVE-2024-48531 is on the confidentiality and integrity of user sessions within eSoft Planner's Rental Availability module. Successful exploitation can lead to theft of session cookies, enabling attackers to impersonate users and access sensitive rental planning data. Additionally, attackers may manipulate the application’s behavior by executing unauthorized actions on behalf of the user. Although availability is not directly affected, the breach of confidentiality and integrity can result in significant operational disruptions, data leakage, and reputational damage. Organizations relying on eSoft Planner for rental management may face increased risk of targeted attacks, especially if attackers leverage social engineering to induce user interaction. The requirement for user interaction and some privilege level reduces the ease of exploitation but does not eliminate risk, particularly in environments with many users or where phishing attacks are common.

To mitigate CVE-2024-48531, organizations should implement strict input validation and output encoding on all user-supplied data within the Rental Availability module to prevent script injection. Employing Content Security Policy (CSP) headers can help restrict the execution of unauthorized scripts. Web Application Firewalls (WAFs) should be configured to detect and block reflected XSS attack patterns targeting this module. User education on phishing and suspicious link avoidance is critical to reduce the risk of user interaction-based exploitation. Monitoring web logs for unusual query parameters or payloads can provide early detection of attempted exploitation. Until an official patch is released by eSoft, consider restricting access to the vulnerable module to trusted users or networks. Regularly update and audit the application and its dependencies to ensure no additional vulnerabilities are present.