CVE-2025-52750 identifies a reflected Cross-site Scripting (XSS) vulnerability in the Juergen Schulze Emu2 software, specifically within the emu2-email-users-2 component. The root cause is improper neutralization of user-supplied input during the generation of web pages, which allows malicious actors to inject executable scripts into HTTP responses. When a victim accesses a crafted URL or interacts with malicious content, the injected script executes in their browser context, potentially compromising session tokens, cookies, or enabling actions on behalf of the user without their consent. The affected versions include Emu2 up to 0.83b, with no patches currently linked or available. This vulnerability does not require prior authentication but does require user interaction, such as clicking a malicious link. Although no active exploits have been reported, the vulnerability represents a significant risk due to the commonality of XSS attacks and their ability to bypass access controls and steal sensitive information. The lack of a CVSS score necessitates an assessment based on impact and exploitability, which indicates a high severity due to the potential for data theft and session hijacking. The vulnerability is particularly relevant to organizations using Emu2 for email user management, as compromised sessions could lead to broader access within enterprise environments. Mitigation strategies should focus on prompt patching, input sanitization, output encoding, and deployment of Content Security Policies to limit script execution. Monitoring for suspicious activity and educating users about phishing risks are also important. Given the vendor and product origin, European countries with higher usage of Emu2, especially Germany, are more susceptible to targeted exploitation. The geopolitical stability and regulatory environment in Europe also emphasize the need for rapid response to such vulnerabilities to maintain data protection compliance.

The primary impact of CVE-2025-52750 is on the confidentiality and integrity of user data within affected Emu2 deployments. Successful exploitation allows attackers to execute arbitrary scripts in the context of a victim's browser, potentially leading to session hijacking, theft of authentication credentials, and unauthorized actions performed on behalf of the user. This can result in unauthorized access to sensitive email user information or administrative functions, undermining trust and operational security. For European organizations, this risk is heightened by stringent data protection regulations such as GDPR, where data breaches can lead to significant legal and financial penalties. Additionally, compromised user sessions could facilitate lateral movement within networks, escalating the threat to availability and integrity of broader systems. The lack of known exploits in the wild reduces immediate risk but does not diminish the potential impact if exploited. The vulnerability's ease of exploitation without authentication but requiring user interaction means phishing or social engineering campaigns could be effective attack vectors. Overall, the threat could disrupt business operations, damage reputation, and expose sensitive personal or corporate data.

1. Monitor the vendor's official channels for patches addressing CVE-2025-52750 and apply them promptly once available. 2. Implement strict input validation on all user-supplied data to ensure that potentially malicious scripts are neutralized before rendering. 3. Employ comprehensive output encoding techniques, such as HTML entity encoding, to prevent script injection during web page generation. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of any injected code. 5. Conduct regular security audits and code reviews focusing on input handling and output generation in Emu2 components. 6. Educate users about the risks of clicking on suspicious links or interacting with untrusted sources to reduce the likelihood of successful phishing attacks. 7. Use web application firewalls (WAFs) configured to detect and block common XSS attack patterns targeting Emu2 endpoints. 8. Limit the exposure of the emu2-email-users-2 interface to trusted networks or VPNs where feasible to reduce attack surface. 9. Implement multi-factor authentication (MFA) for access to Emu2 administrative interfaces to mitigate the impact of stolen credentials. 10. Maintain comprehensive logging and monitoring to detect anomalous activities indicative of exploitation attempts.