CVE-2025-56266: Avigilon Access Control Manager RCE Flaw

CVE-2025-56266 Overview

A Host Header Injection vulnerability exists in Avigilon Access Control Manager (ACM) version 7.10.0.20. This vulnerability allows attackers to execute arbitrary code by supplying a crafted URL that manipulates the HTTP Host header. Host header injection attacks exploit web applications that implicitly trust the Host header value without proper validation, enabling attackers to manipulate server-side behavior and potentially achieve code execution.

Critical Impact

This vulnerability allows unauthenticated remote attackers to execute arbitrary code on affected Avigilon ACM systems through network-based attacks with no user interaction required.

Affected Products

• Avigilon Access Control Manager version 7.10.0.20

Discovery Timeline

• 2025-09-08 - CVE-2025-56266 published to NVD
• 2025-09-12 - Last updated in NVD database

Technical Details for CVE-2025-56266

Vulnerability Analysis

This Host Header Injection vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component) occurs when the Avigilon Access Control Manager application fails to properly validate or sanitize the HTTP Host header before using it in server-side operations. The vulnerability is particularly severe because it requires no authentication and can be exploited remotely over the network without any user interaction.

When a web application blindly trusts the Host header, attackers can inject malicious payloads that influence application behavior. In this case, the vulnerability can be leveraged to achieve arbitrary code execution, making it exceptionally dangerous for physical security infrastructure like access control systems.

Root Cause

The root cause of this vulnerability is the improper neutralization of special elements within the HTTP Host header. The Avigilon ACM application does not adequately validate incoming Host header values before processing them, allowing attacker-controlled data to influence downstream components. This falls under CWE-74, which encompasses injection flaws where untrusted input is not properly sanitized before being used in sensitive operations.

Attack Vector

The attack can be executed remotely over the network. An attacker crafts a malicious HTTP request with a specially manipulated Host header and sends it to the vulnerable Avigilon ACM server. The application processes the malicious header without proper validation, leading to code execution on the target system. No authentication is required, and the attack does not require any user interaction.

The exploitation mechanism involves:

1. Identifying a vulnerable Avigilon ACM instance accessible over the network
2. Crafting an HTTP request with a malicious Host header containing injection payloads
3. Sending the request to the target server
4. The server processes the malicious Host header value in a downstream operation
5. Arbitrary code execution is achieved on the target system

For technical details and proof-of-concept information, refer to the GitHub PoC for Host Header Injection.

Detection Methods for CVE-2025-56266

Indicators of Compromise

• Unusual HTTP requests to Avigilon ACM with malformed or suspicious Host headers
• Unexpected outbound network connections from the ACM server
• Anomalous process execution on the ACM system that deviates from normal operational behavior
• Web server logs containing requests with abnormal Host header values

Detection Strategies

• Monitor HTTP request logs for Host headers that do not match expected domain names or IP addresses
• Implement Web Application Firewall (WAF) rules to detect and block requests with malicious Host header patterns
• Deploy network intrusion detection signatures to identify Host header injection attempts targeting Avigilon systems
• Use endpoint detection and response (EDR) solutions to monitor for unexpected code execution on ACM servers

Monitoring Recommendations

• Enable verbose logging on Avigilon ACM web interfaces to capture all incoming request headers
• Configure alerting for any requests where the Host header deviates from the configured server hostname
• Monitor process creation events on ACM servers for signs of exploitation
• Review access control system audit logs for unauthorized configuration changes

How to Mitigate CVE-2025-56266

Immediate Actions Required

• Restrict network access to Avigilon ACM management interfaces to trusted IP addresses only
• Place vulnerable ACM systems behind a reverse proxy that enforces strict Host header validation
• Implement network segmentation to isolate access control infrastructure from untrusted networks
• Monitor systems for signs of exploitation while awaiting a vendor patch

Patch Information

No vendor security advisory or official patch information is currently available for this vulnerability. Organizations should monitor Avigilon's official security communications and the GitHub CVEs Repository for updates. Contact Avigilon support for remediation guidance specific to your deployment.

Workarounds

• Deploy a reverse proxy or load balancer in front of Avigilon ACM that validates and normalizes Host headers before forwarding requests
• Configure firewall rules to limit access to the ACM web interface to authorized management networks only
• Implement application-layer filtering using a WAF to reject requests with suspicious Host header values
• Consider temporarily disabling external access to ACM interfaces until a patch is available

# Example: Nginx reverse proxy configuration to enforce Host header validation
# Place this in your nginx.conf or site configuration

server {
    listen 443 ssl;
    server_name acm.yourdomain.com;
    
    # Reject requests with invalid Host headers
    if ($host !~ ^(acm\.yourdomain\.com)$) {
        return 444;
    }
    
    location / {
        proxy_pass https://internal-acm-server;
        proxy_set_header Host acm.yourdomain.com;
        proxy_set_header X-Real-IP $remote_addr;
    }
}