CVE-2025-62687

Executive Summary

CVE-2025-62687 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the LogStare Collector application. The flaw allows an attacker to perform unintended operations on behalf of an authenticated user if that user visits a crafted malicious page. With a CVSS score of 6.5 (Medium), the vulnerability requires user interaction but can lead to significant integrity and confidentiality impacts, such as unauthorized configuration changes or data exfiltration. No public exploit code or proof-of-concept is currently available, and the vendor has not released a patch.

Note: This vulnerability is not related to any open-source package ecosystem (NPM, PyPI, Go, Ruby) and does not involve WordPress components. It is a proprietary application by LogStare.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack is launched remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – Attacker does not need prior authentication.
• User Interaction (UI): Required (R) – Victim must click a link or visit a page.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality (C): High (H) – Potential to read sensitive data.
• Integrity (I): High (H) – Potential to modify system state.
• Availability (A): None (N) – No direct impact on availability.

Threat Level: Medium. The requirement for user interaction reduces the likelihood of automated exploitation, but the potential for high-impact actions (e.g., credential theft, configuration tampering) makes it a serious concern for organizations using LogStare Collector.

Deep Dive & Mechanics

The LogStare Collector is a monitoring and data aggregation tool. The CSRF vulnerability stems from the lack of anti-CSRF tokens or origin validation in sensitive state-changing requests (e.g., changing collector settings, adding/removing data sources, or exporting logs).

Attack Flow:

1. An attacker crafts a malicious HTML page containing an auto-submitting form or an image tag that triggers a request to the LogStare Collector's administrative endpoint.
2. The attacker lures an authenticated LogStare user (e.g., via phishing email or social media) to visit this page.
3. The victim's browser, holding a valid session cookie for the LogStare Collector, automatically sends the forged request.
4. The server processes the request as if it came from the legitimate user, performing the attacker's desired action (e.g., creating a new admin account, changing log forwarding destinations, or deleting critical data).

Root Cause: The application does not implement CSRF tokens, does not validate the Origin or Referer headers, and relies solely on session cookies for authentication.

Vulnerable vs. Patched Code

Since no patch is available, the following illustrates a typical vulnerable pattern and a recommended fix.

Vulnerable (PHP-like pseudocode):

<?php
// No CSRF token check
if ($_POST['action'] == 'delete_logs') {
    $log_id = $_POST['log_id'];
    $db->query("DELETE FROM logs WHERE id = $log_id");
    echo "Log deleted.";
}
?>

Patched (Recommended):

<?php
session_start();
// Validate CSRF token
if (!isset($_POST['csrf_token']) || $_POST['csrf_token'] !== $_SESSION['csrf_token']) {
    die("CSRF validation failed.");
}
if ($_POST['action'] == 'delete_logs') {
    $log_id = intval($_POST['log_id']); // Also sanitize input
    $db->query("DELETE FROM logs WHERE id = $log_id");
    echo "Log deleted.";
}
?>

Exploitation & Lab Setup

Red Team

Lab Environment:

• Target: LogStare Collector (any version) running on a local VM (e.g., Ubuntu 22.04).
• Attacker: Kali Linux with a simple HTTP server to host the malicious page.

Exploitation Steps:

1. Identify a state-changing endpoint (e.g., /admin/change_password or /collector/update_config).
2. Craft a malicious HTML page that auto-submits a form to that endpoint.
3. Host the page on a local server: python3 -m http.server 8080.
4. Send the link to the victim (simulated by opening the page in a browser where the user is already logged into LogStare).

Example Malicious HTML:

<html>
<body>
<form action="http://target-logstare/admin/change_password" method="POST" id="csrf_form">
    <input type="hidden" name="new_password" value="hacked123">
    <input type="hidden" name="confirm_password" value="hacked123">
</form>
<script>document.getElementById('csrf_form').submit();</script>
</body>
</html>

Blue Team

Detection & Prevention:

• Monitor for unusual sequences of requests from a single IP to sensitive endpoints.
• Implement CSRF tokens in all state-changing forms.
• Validate the Origin and Referer headers on the server side.
• Use SameSite cookies (set to Strict or Lax).
• Educate users about phishing and not clicking suspicious links while logged into administrative interfaces.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /admin/* or /collector/* endpoints with no Referer header or with a mismatched Origin.
• Logs: Server logs showing POST requests to sensitive endpoints from unexpected referrers (e.g., http://evil.com).
• User Activity: Unauthorized changes to collector configuration, new admin accounts, or unexpected log deletions.
• File System: Presence of malicious HTML files on user workstations (if downloaded).

Detection Engineering

YARA Rule

rule Detect_LogStare_CSRF_Exploit {
    meta:
        description = "Detects malicious HTML pages targeting LogStare Collector CSRF"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62687"
    strings:
        $csrf_form = /<form[^>]*action=["']http:\/\/[^"']*logstare[^"']*["']/ nocase
        $csrf_script = /document\.getElementById\(['"]csrf_form['"]\)\.submit\(\)/ nocase
        $hidden_input = /<input[^>]*type=["']hidden["'][^>]*name=["'](new_password|action|config)["']/ nocase
    condition:
        any of them
}

Sigma Rule

title: Suspicious POST to LogStare Admin Endpoint
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects POST requests to LogStare Collector admin endpoints without a valid Referer header.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-stem|startswith:
            - '/admin/'
            - '/collector/'
    filter:
        cs(User-Agent)|contains: 'Mozilla'
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions from trusted IPs
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-62687 - LogStare CSRF Exploit Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/admin/"; http_uri; nocase; content:"Referer|3a|"; http_header; pcre:"/Referer\x3a\x20(?!https?:\/\/[^\/]*logstare)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the LogStare Collector from untrusted networks (e.g., place behind a VPN or firewall).
2. Implement a Web Application Firewall (WAF) rule to block requests to sensitive endpoints without a valid Referer or Origin header.
3. Monitor logs for suspicious POST requests to /admin/* or /collector/*.

Long-Term Fix:

• Vendor Patch: Await an official update from LogStare. Contact their support for a timeline.
• Custom Fix: If source code is available, add CSRF token validation to all state-changing endpoints.
• User Training: Educate administrators on CSRF risks and safe browsing practices.

Workaround:

• Disable automatic form submission in the browser (not practical).
• Use browser extensions that block cross-origin requests (e.g., uMatrix).

Valters IT