CVE-2025-5343 is a stored Cross-Site Scripting (XSS) vulnerability categorized under CWE-79, affecting Zohocorp's ManageEngine Exchange Reporter Plus product up to version 5721. The vulnerability arises from improper neutralization of user-supplied input during web page generation, specifically within the Instant Search functionality. This flaw allows an attacker with at least low-level privileges (PR:L) to inject malicious scripts that are persistently stored on the server and executed in the context of other users' browsers when they access the affected feature. The CVSS 3.1 base score is 6.3, indicating medium severity, with an attack vector of network (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), and user interaction (UI:R). The impact on confidentiality is low, but integrity is high, as attackers can perform unauthorized actions by leveraging the victim's session or privileges. Availability is not affected. No known exploits are currently in the wild, and no patches have been published by the vendor as of the information date. This vulnerability is significant because ManageEngine Exchange Reporter Plus is widely used for monitoring and reporting on Microsoft Exchange environments, making it a valuable target for attackers seeking to compromise enterprise email infrastructure. The stored XSS can be used to steal session tokens, perform actions on behalf of users, or deliver further payloads within the corporate network.

For European organizations, this vulnerability poses a risk primarily to the integrity of their Exchange reporting and monitoring systems. Exploitation could allow attackers to execute arbitrary scripts in the context of authenticated users, potentially leading to session hijacking, unauthorized configuration changes, or lateral movement within the network. Given the critical role of Exchange Reporter Plus in managing email infrastructure, such attacks could disrupt operational workflows, leak sensitive information, or facilitate further compromise. The requirement for low privileges and user interaction lowers the barrier for exploitation, especially in environments with multiple administrators or helpdesk personnel using the product. Organizations in sectors with high regulatory requirements, such as finance, healthcare, and government, could face compliance issues if this vulnerability is exploited. Additionally, the lack of a patch increases exposure time, necessitating immediate compensating controls to mitigate risk.

Until an official patch is released, European organizations should implement several specific mitigations: 1) Restrict access to the ManageEngine Exchange Reporter Plus interface to trusted administrators only, using network segmentation and firewall rules. 2) Enforce strict input validation and sanitization at the application or proxy level, if possible, to detect and block malicious payloads targeting the Instant Search feature. 3) Monitor logs and user activity for unusual behavior indicative of XSS exploitation attempts, such as unexpected script execution or anomalous search queries. 4) Educate users with access about the risks of interacting with untrusted input and the importance of cautious behavior when using the Instant Search functionality. 5) Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts within the application context. 6) Regularly review and update user privileges to minimize the number of accounts with the ability to trigger this vulnerability. 7) Prepare for rapid deployment of vendor patches once available by maintaining an up-to-date asset inventory and testing environment.