CVE-2025-35970: EPSON/FUJIFILM Auth Bypass Vulnerability

CVE-2025-35970 Overview

CVE-2025-35970 is a high-severity vulnerability affecting multiple products from SEIKO EPSON and FUJIFILM Corporation where the initial administrator password can be easily guessed using information available via SNMP. This insecure default configuration flaw allows remote attackers with SNMP access to gain administrator-level access to affected devices when the default password has not been changed.

Critical Impact

Remote attackers can gain full administrative control over affected printers and multifunction devices by leveraging predictable default credentials derived from SNMP-accessible information, potentially compromising device configurations, print jobs, and network security.

Affected Products

• SEIKO EPSON printer and multifunction devices
• FUJIFILM Corporation printer and multifunction devices
• Products with SNMP services enabled and unchanged default administrator passwords

Discovery Timeline

• 2025-08-07 - CVE-2025-35970 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-35970

Vulnerability Analysis

This vulnerability falls under CWE-1391 (Use of Weak Credentials), representing a fundamental security design flaw in how affected EPSON and FUJIFILM devices handle initial administrator authentication. The core issue stems from the predictable nature of default administrator passwords, which can be derived or guessed using device information exposed through the SNMP protocol.

When these devices are deployed with factory settings, administrators are assigned a default password that correlates with device-specific information accessible via SNMP queries. This creates a dangerous situation where any network-adjacent attacker who can reach the SNMP service can enumerate the necessary information to calculate or guess the administrator password.

The vulnerability requires no user interaction and can be exploited remotely across the network, making it particularly dangerous in enterprise environments where numerous printers may retain default credentials.

Root Cause

The root cause of this vulnerability is the use of weak, predictable default credentials that are derived from or related to device information exposed through SNMP. Rather than generating cryptographically random initial passwords or requiring mandatory password configuration during initial setup, the affected devices use a predictable password generation scheme that creates a false sense of security.

This insecure default configuration violates security best practices that require strong, unique initial credentials that cannot be predicted or derived from publicly accessible device information.

Attack Vector

The attack exploits the network-accessible SNMP service on affected devices. An attacker follows this general approach:

1. The attacker identifies target EPSON or FUJIFILM devices on the network
2. SNMP queries are sent to enumerate device information (serial numbers, model information, MAC addresses, or other identifiers)
3. Using the gathered SNMP data, the attacker derives or guesses the default administrator password
4. The attacker authenticates to the device's administrative interface with full privileges
5. With administrator access, the attacker can modify device configurations, intercept print jobs, pivot to other network resources, or establish persistence

The attack requires network access to the SNMP service (typically UDP port 161) and the device's administrative interface. No authentication bypass is needed—the attacker simply uses the predictable default credentials.

Detection Methods for CVE-2025-35970

Indicators of Compromise

• Unusual SNMP query patterns targeting printer devices, particularly bulk information requests
• Multiple failed login attempts followed by successful administrator authentication on printer web interfaces
• Configuration changes on printer devices that were not authorized by IT staff
• New or modified user accounts on affected devices
• Changes to network settings, print queues, or security configurations

Detection Strategies

• Monitor SNMP traffic (UDP port 161) for enumeration patterns targeting printer devices
• Implement authentication logging on printer administrative interfaces and alert on successful logins from unexpected sources
• Deploy network segmentation to isolate printer management interfaces and monitor cross-segment access attempts
• Use network scanning tools to identify devices still using default credentials

Monitoring Recommendations

• Configure SIEM rules to correlate SNMP enumeration activity with subsequent administrative logins on affected device types
• Establish baselines for normal SNMP traffic patterns and alert on deviations
• Implement regular automated audits to identify devices with unchanged default passwords
• Monitor for unauthorized firmware updates or configuration exports from printer devices

How to Mitigate CVE-2025-35970

Immediate Actions Required

• Change default administrator passwords on all affected EPSON and FUJIFILM devices immediately
• Disable SNMP services if not required for device management
• If SNMP is required, configure SNMPv3 with strong authentication and encryption
• Restrict network access to printer management interfaces using firewall rules or VLANs
• Audit all deployed devices to identify those with default credentials still in use

Patch Information

SEIKO EPSON and FUJIFILM Corporation have acknowledged this vulnerability and provided guidance through their respective support channels. Organizations should review the official advisories for device-specific mitigation steps:

• Fujifilm News Announcement
• Epson Support Notice
• JVN Vulnerability Report

Consult vendor documentation for firmware updates that may address the underlying credential generation mechanism.

Workarounds

• Implement network segmentation to isolate printer devices on dedicated management VLANs
• Use access control lists (ACLs) to restrict SNMP access to authorized management stations only
• Deploy a jump host or bastion server for printer administration, limiting direct network access
• Consider implementing 802.1X network access control to prevent unauthorized devices from querying printers
• Enable logging and alerting on all printer administrative interfaces to detect unauthorized access attempts

# Example: Restrict SNMP access using iptables (Linux-based print server)
# Allow SNMP only from authorized management subnet
iptables -A INPUT -p udp --dport 161 -s 10.10.50.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 161 -j DROP

# Example: Disable SNMPv1/v2c and enable SNMPv3 (device-specific commands vary)
# Consult your device documentation for specific configuration steps