Home Notice DoS Vulnerability in the Web Connection of Konica Minolta Multifunction Printers

DoS Vulnerability in the Web Connection of Konica Minolta Multifunction Printers

| 18 September 2025

DoS Vulnerability in the Web Connection of Konica Minolta Multifunction Printers

Dear Customers,

We deeply appreciate your constant patronage to Konica Minolta products.

A vulnerability that allows a Denial-of-Service (DoS) attack has been newly identified in the indicated models. This advisory provides an overview of the issue and the recommended countermeasures.

Please note that, at the time of publication (August 29th, 2025), there have been no confirmed security incidents globally resulting from the exploitation of this vulnerability.

Overview of the vulnerabilities

Ref. ID	CVSSv3.1	Base Score	Vulnerabilities description
CVE-2025-54777	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L	4.3	Importing a malformed file in [Registration of Certification Information] for S/MIME for Email Destination causes the Web Connection to stop.

Affected Models and the countermeasure firmware

Product name	Affected Version	Fixed Version	Latest Version (as of August 2025)
bizhub C751i bizhub C651i/C551i/C451i bizhub C361i/C301i/C251i bizhub C4051i/C3351i/C4001i/C3301i bizhub C3321i bizhub 751i bizhub 651i/551i/451i bizhub 361i/301i bizhub 4751i/4051i bizhub 4701i bizhub C750i bizhub C650i/C550i/C450i bizhub C360i/C300i/C250i bizhub C287i/C257i/C227i bizhub C4050i/C3350i/C4000i/C3300i bizhub C3320i bizhub 950i/850i bizhub 750i bizhub 650i/550i/450i bizhub 360i/300i bizhub 306i/266i/246i/226i bizhub 4750i/4050i bizhub 4700i	G00-RE or earlier	GC2-RE or later (Except G00-RF)	G00-S7
bizhub C759/C659 bizhub C658/C558/C458 bizhub 958/808/758 bizhub 658e/558e/458e bizhub C287/C227	GCQ-Y2 or earlier	GCR-Y2 or later	G00-YE
bizhub C368/C308/C258 bizhub 558/458/368/308 bizhub C3851/C3851FS/C3351 bizhub 4752/4052	GCQ-X4 or earlier	GCR-X4 or later	G00-YE
bizhub 368e/308e	GCQ-X8 or earlier	GCR-X8 or later	G00-YE
bizhub 367/287/227	GCQ-Y3 or earlier	GCR-Y3 or later	G00-YE

Impact on Multifunction Printers

Web Connection becomes completely unresponsive. (Other MFP functions are not affected.)

Remediation

The countermeasure firmware will be applied sequentially, either remotely or during the next visit by your authorised Konica Minolta service representative.

Vulnerability Specific Recommendation

1. Ensure that the administrator password is secure. If it remains set to its factory default, please change it immediately to a strong complex password.
Configuration: [Utility] - [Administrator] - [Security] - [Administrator Password Setting]

2. Restrict non-Admin users from making any address book destination changes.
Configuration: [Utility] - [Administrator] - [Security] - [Restrict User Access] - [Registering and Changing Addresses]: [Restrict]

General Security Recommendations

To ensure a secure operating posture for your multifunction devices, and to reduce exposure to the vulnerability described in this advisory, Konica Minolta strongly recommends applying the following configuration best practices:

1. Avoid Direct Internet Exposure

Place devices behind firewalls and use private IP addressing and Device IP Filtering settings.

2. Change Default Passwords

Change default credentials and implement strong passwords for administrative and network functions.

3. Use Strong Passwords for Services

Ensure strong credentials are configured for SMTP, LDAP, SMB, WebDAV, and any other integrated services.

4. Disable Unused Services

Turn off unused ports or protocols to reduce attack surface.

5. Use Secure Protocols

Configure devices to use encrypted communications (e.g., HTTPS, LDAPS, IPPS) where supported.

6. Monitor Device Activity

Regularly review device logs and network traffic for suspicious behavior.

7. Enable Authentication Where Available

Use built-in user authentication features to prevent unauthorised access to device functions.

For comprehensive information on secure configuration, please refer to our Product Security web site.

More Information

Enhancing the Security of Products and Services

Konica Minolta considers the security of its products and services to be an important responsibility and will continue to actively respond to incidents and vulnerabilities.

More Information

Related Information

JVNVU#99831542

Acknowledgements

We would like to express our sincere appreciation to the penetration testers Miguel Alves (0xmupa) for discovering and responsibly reporting this vulnerability.

Contacts

Should you require further clarification or assistance with implementing the recommended measures or applying the relevant firmware update, please contact your authorised Konica Minolta service representative.