CVE-2024-11610

Executive Summary

CVE-2024-11610 is a critical memory corruption vulnerability in AutomationDirect C-More EA9 HMI (Human-Machine Interface) panels. The flaw resides in the parsing of EAP9 project files, where insufficient validation of user-supplied data can lead to a memory corruption condition. An attacker can exploit this by convincing a user to open a malicious EAP9 file or visit a crafted web page, leading to remote code execution in the context of the current process. With a CVSS score of 7.8, this vulnerability poses a significant risk to industrial control systems (ICS) environments, potentially allowing attackers to gain a foothold in OT networks. No public proof-of-concept (PoC) or patch is currently available, making detection and mitigation critical.

CVSS Breakdown & Threat Level

• CVSS Score: 7.8 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
• Attack Vector (AV): Network – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): None – No authentication needed.
• User Interaction (UI): Required – The target must open a malicious file or visit a malicious page.
• Scope (S): Unchanged – The exploit affects only the vulnerable component.
• Confidentiality (C): High – Full data access possible.
• Integrity (I): High – Full data modification possible.
• Availability (A): High – Full system denial of service possible.

Threat Level: High. The vulnerability is remotely exploitable with low complexity, and while user interaction is required, social engineering in OT environments is often effective. The lack of a patch increases the risk.

Deep Dive & Mechanics

The vulnerability exists in the EAP9 file parser of AutomationDirect C-More EA9 HMI software. EAP9 files are project files used to configure HMI screens, tags, and logic. The parser fails to properly validate the size or structure of user-supplied data within these files, leading to a memory corruption condition (likely a buffer overflow or use-after-free).

Technical Breakdown:

1. Trigger: The attacker crafts a malicious EAP9 file with oversized or malformed data in a specific field (e.g., a string length or array index).
2. Parsing: When the C-More EA9 software opens the file, the parser copies the attacker-controlled data into a fixed-size buffer without bounds checking.
3. Memory Corruption: The overflow overwrites adjacent memory regions, including function pointers or return addresses.
4. Code Execution: The attacker can control the overwritten data to redirect execution flow to shellcode, achieving arbitrary code execution in the context of the HMI software.

Root Cause: Lack of proper input validation (CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer).

Vulnerable vs. Patched Code

Since no patch is available, a direct comparison is not possible. However, based on the vulnerability description, the vulnerable code likely resembles:

// Vulnerable pseudo-code
void parse_EAP9_field(char *input, int len) {
    char buffer[256];
    memcpy(buffer, input, len); // No bounds check
}

A patched version would include validation:

// Patched pseudo-code
void parse_EAP9_field(char *input, int len) {
    char buffer[256];
    if (len > sizeof(buffer)) {
        // Handle error
        return;
    }
    memcpy(buffer, input, len);
}

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• AutomationDirect C-More EA9 software (vulnerable version)
• A malicious EAP9 file crafted with a buffer overflow payload
• A target system running the vulnerable software

Exploitation Steps:

1. Craft Malicious EAP9 File: Use a fuzzer or manual analysis to identify the overflow point. Create an EAP9 file with a long string in a vulnerable field.
2. Deliver Payload: Host the file on a web server or send via email/social engineering.
3. Trigger: Convince the user to open the file in C-More EA9.
4. Execute: The overflow overwrites a return address or function pointer, redirecting execution to shellcode.

Example Payload Structure (Conceptual):

# Python script to generate malicious EAP9 file (conceptual)
payload = b"A" * 256  # Fill buffer
payload += b"\x90" * 100  # NOP sled
payload += shellcode  # e.g., calc.exe or reverse shell
# Write to EAP9 file
with open("malicious.eap9", "wb") as f:
    f.write(payload)

Note: No public exploit code is available. This is a conceptual example.

Blue Team (Defensive)

Detection & Prevention:

• Network Segmentation: Isolate HMI systems from the corporate network and internet.
• File Integrity Monitoring: Monitor for unauthorized EAP9 file modifications.
• User Training: Educate operators not to open untrusted files.
• Application Whitelisting: Only allow trusted software to execute.
• Sandboxing: Open EAP9 files in a sandboxed environment.

Indicators of Compromise (IOCs)

• File Hashes (Malicious EAP9): Unknown (no public samples)
• Network Traffic: Unusual outbound connections from HMI software (e.g., to attacker C2)
• Process Behavior: C-More EA9 process crashing or exhibiting abnormal memory usage
• Registry/File System: Creation of suspicious files in temp directories
• Logs: Event ID 1000 (Application Error) in Windows Event Viewer for C-More EA9

Detection Engineering

YARA Rule

rule CVE_2024_11610_Malicious_EAP9 {
    meta:
        description = "Detects malicious EAP9 files exploiting CVE-2024-11610"
        author = "Valters IT"
        date = "2025-04-10"
        hash = "unknown"
    strings:
        $magic = { 45 41 50 39 } // "EAP9" magic bytes
        $overflow = /.{256,}/ // Potential overflow pattern
    condition:
        $magic at 0 and #overflow > 0
}

Sigma Rule

title: C-More EA9 EAP9 File Parsing Memory Corruption
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential exploitation of CVE-2024-11610 via process crash or abnormal memory access
author: Valters IT
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: 'CMoreEA9.exe'
        CommandLine|contains: '.eap9'
    condition: selection
falsepositives:
    - Legitimate EAP9 file opening
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-11610 C-More EA9 EAP9 File Download"; flow:to_server,established; content:"EAP9"; nocase; fileext:"eap9"; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable Auto-Open: Configure systems to not automatically open EAP9 files.
2. Network Controls: Block inbound/outbound connections to/from HMI systems except for essential services.
3. User Awareness: Train operators to verify file sources before opening.

Long-Term Fix:

• Vendor Patch: Await an official patch from AutomationDirect. Monitor their security advisories.
• Workaround: If possible, use alternative HMI software or restrict file parsing to trusted sources only.
• Compensating Controls: Deploy endpoint detection and response (EDR) solutions with behavioral analysis.

Valters IT Signature This report was generated by Valters IT Cyber Threat Intelligence. For questions, contact intelligence@valters-it.com.