CVE-2024-23486: Buffalo WSR-2533DHP Password Disclosure

CVE-2024-23486 Overview

CVE-2024-23486 is a plaintext storage of password vulnerability affecting multiple BUFFALO wireless LAN router models. This firmware vulnerability allows a network-adjacent unauthenticated attacker with access to the product's login page to obtain configured credentials stored in plaintext. The insecure credential storage mechanism exposes administrative passwords without proper encryption or hashing, creating a significant risk for network compromise.

Critical Impact

Unauthenticated attackers on the local network can extract administrative credentials stored in plaintext, potentially gaining full control over affected BUFFALO routers and the networks they protect.

Affected Products

• BUFFALO WSR-2533DHP (Firmware)
• BUFFALO WSR-2533DHPL (Firmware)
• BUFFALO WSR-2533DHP2 (Firmware)
• BUFFALO WSR-A2533DHP2 (Firmware)

Discovery Timeline

• April 10, 2024 - BUFFALO releases security update addressing the vulnerability
• April 15, 2024 - CVE-2024-23486 published to NVD
• June 30, 2025 - Last updated in NVD database

Technical Details for CVE-2024-23486

Vulnerability Analysis

This vulnerability is classified under CWE-256 (Unprotected Storage of Credentials), a critical security weakness where sensitive authentication data is stored without adequate protection. The affected BUFFALO router firmware stores administrative passwords in plaintext format, making them directly accessible to attackers who can reach the router's login page from the local network.

The vulnerability is particularly concerning because it requires no authentication to exploit. An attacker positioned on the same network segment as the vulnerable router can potentially access the login page and retrieve credentials without needing prior access to the device. This represents a fundamental design flaw in how the router firmware handles credential storage.

The network-based attack vector means that any device connected to the same local network—whether through WiFi or ethernet—could potentially be used to launch an attack against the router. This includes compromised IoT devices, guest network users, or malicious actors who have gained initial network access through other means.

Root Cause

The root cause of CVE-2024-23486 lies in the firmware's failure to implement proper credential protection mechanisms. Instead of storing passwords using secure hashing algorithms (such as bcrypt, scrypt, or Argon2) with appropriate salting, the BUFFALO router firmware stores passwords in their original plaintext form. This violates fundamental security principles for credential storage and exposes users to credential theft attacks.

Attack Vector

The attack vector for this vulnerability is network-based, targeting the router's web management interface. An attacker must be positioned on the same network as the vulnerable router to exploit this vulnerability. The attack flow involves:

1. The attacker gains access to the local network (through legitimate access, compromised device, or WiFi infiltration)
2. The attacker accesses the router's login page or web management interface
3. Due to improper credential storage, the plaintext password can be extracted from the interface or underlying storage
4. With obtained credentials, the attacker gains full administrative access to the router

Once administrative access is obtained, attackers can modify DNS settings for traffic interception, create persistent backdoor access, pivot to attack other network devices, or disable security features to facilitate further attacks.

Detection Methods for CVE-2024-23486

Indicators of Compromise

• Unauthorized access attempts to the router's web management interface from unexpected internal IP addresses
• Unexpected configuration changes to DNS servers, firewall rules, or administrative credentials
• Unusual login activity patterns in router logs, particularly from devices not typically used for administration
• Modified firmware or unexpected firmware version mismatches

Detection Strategies

• Monitor network traffic for unusual access patterns to the router's management ports (typically HTTP/HTTPS on ports 80/443)
• Implement network segmentation to isolate router management interfaces from general user networks
• Deploy intrusion detection systems (IDS) configured to alert on router management interface access from unauthorized sources
• Regularly audit router configuration for unexpected changes

Monitoring Recommendations

• Enable and review router access logs if supported by the firmware
• Configure network monitoring tools to track all connections to the router's management interface
• Implement alerts for any configuration changes made to the router
• Monitor for new DHCP clients that may indicate unauthorized network access

How to Mitigate CVE-2024-23486

Immediate Actions Required

• Update affected BUFFALO router firmware to the latest version immediately
• Change all administrative passwords after applying the firmware update
• Restrict management interface access to specific trusted IP addresses or VLANs
• Disable remote management features if not required

Patch Information

BUFFALO has released firmware updates to address this vulnerability. Users should visit the BUFFALO Security Update page to download the appropriate firmware for their router model. Additional technical details are available in the JVN Security Advisory. All affected router models (WSR-2533DHP, WSR-2533DHPL, WSR-2533DHP2, WSR-A2533DHP2) should be updated to the patched firmware versions as soon as possible.

Workarounds

• Restrict access to the router management interface to trusted devices only using MAC address filtering or IP-based access controls
• Place the router management interface on a separate VLAN accessible only by authorized administrators
• Disable WiFi access to the management interface if wired management is sufficient
• Monitor network for unauthorized access attempts while awaiting firmware updates

# Example network segmentation configuration (general guidance)
# Create a dedicated management VLAN for router administration
# Only allow specific administrator IP addresses to access management interface
# Disable WAN-side management access
# Enable logging for all management interface access attempts