CVE-2025-48046 is a medium-severity vulnerability identified in the NetFax Server product developed by MICI Network Co. Ltd. The vulnerability is classified under CWE-256, which pertains to the plaintext storage of passwords. Specifically, this flaw allows an authenticated user to retrieve the cleartext password of a configured SMTP server by sending an HTTP GET request to the /config.php endpoint. This means that once an attacker has valid credentials to access the NetFax Server, they can exploit this vulnerability to disclose sensitive SMTP credentials without any additional user interaction or elevated privileges beyond authentication. The vulnerability has a CVSS 4.0 base score of 5.3, reflecting a network attack vector with low complexity and requiring low privileges but no user interaction. The impact is limited to confidentiality, as the attacker can obtain the SMTP password, which could then be used to send unauthorized emails or further compromise the organization's email infrastructure. No known exploits are currently reported in the wild, and no patches have been published at the time of disclosure. The affected version is listed as '0', which likely indicates an initial or unspecified version, suggesting that all current versions prior to a patch are vulnerable. The vulnerability does not affect integrity or availability directly but poses a risk of credential leakage that could lead to broader security issues if the SMTP credentials are reused or provide access to critical email systems.

For European organizations using MICI Network Co. Ltd.'s NetFax Server, this vulnerability presents a significant risk to the confidentiality of SMTP credentials. Disclosure of these credentials could enable attackers to send spoofed or phishing emails from legitimate company domains, potentially damaging brand reputation and facilitating further attacks such as business email compromise (BEC). Additionally, unauthorized access to SMTP servers could allow attackers to intercept or manipulate email traffic, impacting sensitive communications. Given the vulnerability requires authentication, the initial barrier is the compromise or legitimate possession of user credentials, which could be obtained through phishing or insider threats. The impact is heightened for organizations relying heavily on NetFax Server for critical fax-to-email workflows, especially in regulated sectors such as finance, healthcare, and government within Europe, where data protection laws like GDPR impose strict requirements on protecting personal data and credentials. Failure to secure these credentials could lead to regulatory penalties and loss of customer trust.

To mitigate this vulnerability, European organizations should first restrict access to the NetFax Server's management interface to trusted administrative users and networks, employing network segmentation and strict access controls. Implement strong authentication mechanisms, including multi-factor authentication (MFA), to reduce the risk of credential compromise. Since no patches are currently available, organizations should monitor for updates from MICI Network Co. Ltd. and apply them promptly once released. As an immediate workaround, consider disabling or restricting access to the /config.php endpoint if feasible, or employ web application firewalls (WAFs) to detect and block suspicious HTTP GET requests targeting this endpoint. Regularly audit and rotate SMTP credentials to limit the window of exposure in case of compromise. Additionally, monitor SMTP server logs for unusual activity indicative of unauthorized use. Finally, educate users and administrators about the risks of credential exposure and enforce policies to prevent password reuse across systems.