CVE-2025-34050

Executive Summary

CVE-2025-34050 is a critical Cross-Site Request Forgery (CSRF) vulnerability affecting the web interface of AVTECH IP cameras, DVRs, and NVRs. An attacker can craft malicious requests that, when executed in the context of an authenticated user’s browser session, allow unauthorized changes to device configuration without user interaction. This vulnerability is particularly dangerous for organizations relying on AVTECH surveillance equipment for physical security, as it could allow an attacker to disable recording, modify network settings, or exfiltrate video feeds. No public proof-of-concept (PoC) or exploit code has been released, and no official patch is available from the vendor.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (NVD base score not assigned; estimated based on vector)
• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must be authenticated and click a link)
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: High
• Availability Impact: None
• Threat Level: High (due to potential for complete device compromise via configuration changes)

Deep Dive & Mechanics

The vulnerability resides in the web interface of AVTECH devices, which lacks proper CSRF tokens or origin validation on configuration-changing endpoints. An attacker can craft a malicious HTML page or email that, when visited by an authenticated administrator, silently sends requests to the device’s web interface (e.g., http://<device-ip>/cgi-bin/config.cgi?action=set&param=...). Because the browser automatically includes the session cookie, the device processes the request as legitimate.

Key affected endpoints likely include:

• /cgi-bin/config.cgi – for modifying device settings
• /cgi-bin/user.cgi – for adding/removing users
• /cgi-bin/network.cgi – for changing network parameters

The attack does not require the attacker to know the victim’s credentials, only that the victim is currently authenticated to the device. This makes it a classic CSRF scenario.

Vulnerable vs. Patched Code

No patched code is available. The vulnerable code likely lacks a CSRF token check. A secure implementation would include:

Vulnerable (pseudo-code):

def handle_config_change(request):
    # No CSRF token validation
    param = request.GET.get('param')
    value = request.GET.get('value')
    set_config(param, value)

Patched (pseudo-code):

def handle_config_change(request):
    token = request.GET.get('csrf_token')
    if not validate_csrf_token(token, request.session):
        return "Invalid CSRF token"
    param = request.GET.get('param')
    value = request.GET.get('value')
    set_config(param, value)

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy an AVTECH device (e.g., IP camera) on an isolated network.
2. Authenticate as admin via browser.
3. Create a malicious HTML page that sends a CSRF request to change the admin password.

Example Malicious HTML:

<html>
<body>
<h1>Click me for a surprise!</h1>
<img src="http://192.168.1.100/cgi-bin/user.cgi?action=set&user=admin&password=newpass123" style="display:none;">
</body>
</html>

Execution:

• Host the HTML on a server the victim can access.
• Send a phishing link to the victim (who must be authenticated to the AVTECH device).
• Once the victim clicks, the password is changed, granting the attacker access.

Blue Team

Detection:

• Monitor for unusual HTTP requests to AVTECH device IPs, especially cgi-bin endpoints with action=set parameters.
• Look for Referer headers that do not match the device’s domain.
• Use network segmentation to isolate AVTECH devices from user workstations.

Prevention:

• Implement a reverse proxy with CSRF protection in front of the device.
• Disable the web interface if not needed, or restrict access via firewall rules.
• Train users not to browse other sites while authenticated to the device.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /cgi-bin/config.cgi, /cgi-bin/user.cgi, /cgi-bin/network.cgi with action=set or action=add parameters.
  • Referer header not matching the device’s IP or domain.
  • Unusual User-Agent strings (e.g., from automated tools).
• Host IOCs:
  • Unexpected changes to device configuration (e.g., new admin users, changed passwords, disabled recording).
  • Log entries showing configuration changes without corresponding user login events.

Detection Engineering

YARA Rule

rule CVE_2025_34050_CSRF_AVTECH {
    meta:
        description = "Detects CSRF attempts against AVTECH devices"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-34050"
    strings:
        $cgi = "/cgi-bin/" nocase
        $action_set = "action=set" nocase
        $action_add = "action=add" nocase
    condition:
        any of ($cgi*) and any of ($action_set, $action_add)
}

Sigma Rule

title: CSRF Attempt Against AVTECH Device
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects HTTP requests targeting AVTECH device configuration endpoints
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '/cgi-bin/config.cgi'
            - '/cgi-bin/user.cgi'
            - '/cgi-bin/network.cgi'
        cs-uri-query|contains:
            - 'action=set'
            - 'action=add'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-34050 CSRF Attempt Against AVTECH Device"; flow:to_server; content:"/cgi-bin/"; http_uri; content:"action=set" or content:"action=add"; http_uri; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Isolate AVTECH devices on a separate VLAN with strict firewall rules.
   • Disable the web interface if not required for operations.
   • Use a reverse proxy (e.g., Nginx) to add CSRF tokens to all requests.

2. Long-term Fix:

   • Contact AVTECH for a firmware update that includes CSRF protection.
   • If no patch is available, consider replacing the devices with alternatives that have proper security controls.

3. User Training:

   • Educate administrators to log out of the device web interface when not in use.
   • Avoid clicking links or visiting untrusted sites while authenticated to the device.

4. Monitoring:

   • Deploy the provided YARA, Sigma, and Suricata rules to detect exploitation attempts.
   • Regularly audit device logs for unauthorized configuration changes.

Valters IT
DevSecOps & Cyber Threat Intelligence