CVE-2025-6560: Sapido Router Information Disclosure Flaw

CVE-2025-6560 Overview

Multiple wireless router models from Sapido contain an Exposure of Sensitive Information vulnerability that allows unauthenticated remote attackers to directly access a system configuration file and obtain plaintext administrator credentials. This vulnerability enables complete compromise of affected devices without any prior authentication, posing a severe risk to network security.

The affected models are end-of-life and no longer receiving security updates from the vendor. Device replacement is the recommended course of action.

Critical Impact

Unauthenticated remote attackers can obtain plaintext administrator credentials and gain full control over affected Sapido wireless routers, potentially compromising entire network segments.

Affected Products

• Sapido wireless router models (multiple models affected - specific models listed in TW-CERT advisory)
• End-of-life Sapido router firmware versions
• Network devices exposing configuration files without authentication

Discovery Timeline

• 2025-06-24 - CVE-2025-6560 published to NVD
• 2025-06-26 - Last updated in NVD database

Technical Details for CVE-2025-6560

Vulnerability Analysis

This vulnerability falls under CWE-256 (Plaintext Storage of a Password), representing a critical security design flaw in the affected Sapido wireless routers. The vulnerability allows unauthenticated remote attackers to access system configuration files that contain administrator credentials stored in plaintext format.

The attack requires no authentication, no user interaction, and can be executed remotely over the network. Once an attacker retrieves the plaintext credentials, they gain complete administrative control over the router, enabling them to modify network configurations, intercept traffic, pivot to internal networks, or use the device as part of a botnet.

The fundamental issue stems from two compounding security failures: the storage of sensitive credentials without proper encryption or hashing, and the exposure of configuration files without access controls.

Root Cause

The root cause is the combination of improper access control on sensitive configuration files and the storage of administrator passwords in plaintext (CWE-256). The router firmware fails to implement proper authentication requirements for accessing configuration endpoints and does not employ password hashing or encryption for stored credentials.

Attack Vector

The attack is network-based, requiring the attacker to have network access to the vulnerable router's management interface. The attacker sends an unauthenticated HTTP request to retrieve the exposed configuration file. The response contains the administrator username and password in plaintext, which can then be used to authenticate to the router's administrative interface and take full control of the device.

Successful exploitation allows attackers to:

• Modify DNS settings to redirect traffic
• Create persistent backdoor access
• Intercept and manipulate network traffic
• Use the router as a pivot point for lateral movement
• Enroll the device in IoT botnets

Detection Methods for CVE-2025-6560

Indicators of Compromise

• Unexpected HTTP requests to router configuration file endpoints from external IP addresses
• Unauthorized administrative login attempts or successful logins from unknown sources
• Changes to router configuration including DNS settings, firewall rules, or port forwarding without administrator action
• Unusual outbound connections from the router to unknown external IP addresses

Detection Strategies

• Monitor network traffic for unauthenticated requests targeting router configuration endpoints
• Implement network segmentation to isolate management interfaces from untrusted networks
• Deploy intrusion detection systems with signatures for known router exploitation patterns
• Review router access logs for unauthorized configuration file access attempts

Monitoring Recommendations

• Enable logging on router management interfaces where supported
• Monitor for unauthorized changes to DNS, firewall, and routing configurations
• Implement network traffic analysis to detect credential exfiltration attempts
• Set up alerts for administrative logins from unexpected IP addresses or at unusual times

How to Mitigate CVE-2025-6560

Immediate Actions Required

• Replace affected Sapido router models with currently supported devices from vendors providing regular security updates
• If immediate replacement is not possible, restrict management interface access to trusted internal networks only
• Disable remote management features and WAN-side administrative access
• Implement network segmentation to isolate vulnerable devices
• Change administrator credentials and monitor for unauthorized access

Patch Information

The affected Sapido router models are end-of-life and no longer receiving security updates. No patch is available from the vendor. The official recommendation from TW-CERT is to replace affected devices with supported alternatives. For additional details, refer to the TW-CERT Security Advisory.

Workarounds

• Disable WAN-side management access to prevent remote exploitation
• Place routers behind a firewall that blocks external access to management interfaces
• Implement access control lists (ACLs) to restrict management interface access to specific trusted IP addresses
• Use VPN for remote administration instead of exposing management interfaces directly
• Monitor network traffic for signs of exploitation while planning device replacement

# Example: Restrict management access (if router CLI is available)
# These commands are conceptual - exact syntax varies by firmware
# Consult your device documentation before applying

# Disable remote/WAN management
set remote-management disable

# Restrict management to specific subnet
set management-access allowed-network 192.168.1.0/24

# Enable access logging
set management-logging enable