CVE-2025-24617 is a reflected Cross-site Scripting (XSS) vulnerability found in the AcyMailing SMTP Newsletter component developed by the AcyMailing Newsletter Team. The vulnerability exists due to improper neutralization of input during web page generation, which allows an attacker to inject malicious JavaScript code into web pages viewed by other users. Specifically, this affects versions prior to 9.11.1 of the AcyMailing SMTP Newsletter. Reflected XSS vulnerabilities occur when untrusted input is immediately included in web responses without adequate sanitization or encoding, enabling attackers to craft URLs or forms that execute arbitrary scripts in the victim’s browser. These scripts can hijack user sessions, steal cookies, perform actions on behalf of the user, or redirect users to malicious sites. The vulnerability does not require prior authentication, increasing its risk profile, and typically relies on social engineering to lure victims into clicking malicious links. Although no public exploits have been reported yet, the vulnerability was publicly disclosed on February 14, 2025, and remains unpatched in versions before 9.11.1. The absence of a CVSS score necessitates a severity assessment based on impact and exploitability factors. Given the widespread use of AcyMailing in Joomla and WordPress environments, this vulnerability poses a significant risk to organizations relying on these platforms for email marketing and newsletter distribution.

The potential impact of CVE-2025-24617 is significant for organizations using vulnerable versions of AcyMailing SMTP Newsletter. Successful exploitation can lead to unauthorized script execution in users’ browsers, resulting in session hijacking, credential theft, unauthorized actions on behalf of users, and potential malware distribution. This can compromise user accounts, lead to data breaches, and damage organizational reputation. Since the vulnerability is reflected XSS, it requires user interaction, but the ease of crafting malicious links makes widespread phishing campaigns feasible. Organizations that rely heavily on AcyMailing for customer communications or internal newsletters may face disruption and loss of trust. Additionally, attackers could leverage this vulnerability as a foothold for further attacks within the network or to escalate privileges. The lack of authentication requirement broadens the attack surface, potentially affecting any user who interacts with the malicious payload. Overall, the vulnerability threatens confidentiality and integrity of user data and can indirectly impact availability if exploited to deploy further attacks or malware.

To mitigate CVE-2025-24617, organizations should immediately upgrade AcyMailing SMTP Newsletter to version 9.11.1 or later, where the vulnerability is patched. If upgrading is not immediately possible, implement strict input validation and output encoding on all user-supplied data within the newsletter component to neutralize potentially malicious scripts. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Educate users about the risks of clicking unsolicited or suspicious links, especially those appearing in newsletters or emails. Monitor web server logs and application behavior for unusual requests that may indicate exploitation attempts. Additionally, consider deploying Web Application Firewalls (WAFs) with rules to detect and block reflected XSS payloads targeting AcyMailing endpoints. Regularly audit and update all third-party plugins and components to reduce exposure to similar vulnerabilities. Finally, maintain an incident response plan to quickly address any successful exploitation.