CVE-2024-11801

Executive Summary

CVE-2024-11801 is a critical Out-Of-Bounds Write vulnerability in Fuji Electric Tellus Lite V-Simulator 5, specifically during the parsing of V8 files. This flaw allows remote code execution (RCE) in the context of the current process, requiring user interaction (e.g., opening a malicious file or visiting a malicious page). The vulnerability has a CVSS score of 7.8 (High) and is currently unpatched. No public proof-of-concept (PoC) or exploit code has been identified, but the risk remains significant for industrial control system (ICS) environments.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
• Base Score: 7.8 (High)
• Attack Vector: Local (requires user interaction)
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: High. Exploitation could lead to full system compromise within the user's session, potentially allowing lateral movement in ICS networks.

Deep Dive & Mechanics

The vulnerability resides in the V8 file parsing component of Fuji Electric Tellus Lite V-Simulator 5. The software fails to validate user-supplied data properly, leading to a write past the end of an allocated data structure (Out-Of-Bounds Write). This memory corruption can be leveraged by an attacker to execute arbitrary code.

Root Cause: Lack of bounds checking when processing V8 file data, allowing an attacker to control the write destination and overwrite critical memory regions (e.g., function pointers, return addresses).

Attack Vector: The attacker must convince a user to open a malicious V8 file or visit a malicious page that triggers the file parsing. This is typical for client-side vulnerabilities in engineering software.

Vulnerable vs. Patched Code

No patched version is available. The vulnerable code likely resides in the V8 parser module (e.g., V8Parser.dll or similar). A hypothetical fix would involve adding bounds checks before memory write operations.

Vulnerable Code (Conceptual):

void parse_v8_data(char *input, size_t len) {
    char *buffer = malloc(256);
    memcpy(buffer, input, len); // No bounds check
}

Patched Code (Conceptual):

void parse_v8_data(char *input, size_t len) {
    char *buffer = malloc(256);
    if (len > 256) {
        // Handle error
        return;
    }
    memcpy(buffer, input, len);
}

Exploitation & Lab Setup

Red Team

Prerequisites:

• Fuji Electric Tellus Lite V-Simulator 5 installed on a Windows target.
• Ability to deliver a malicious V8 file (e.g., via phishing email or malicious website).

Exploitation Steps:

1. Craft a malicious V8 file with a crafted header or data section that triggers an out-of-bounds write.
2. Use a memory corruption technique (e.g., ROP chain) to achieve code execution.
3. Deliver the file to the target and convince them to open it.

Example Payload Generation (Conceptual):

# This is a conceptual example; no public exploit exists.
import struct

payload = b"A" * 256  # Trigger overflow
payload += struct.pack("<I", 0xdeadbeef)  # Overwrite return address
with open("malicious.v8", "wb") as f:
    f.write(payload)

Blue Team

Detection:

• Monitor for unusual file access patterns to V8 files.
• Use process monitoring to detect crashes or abnormal memory access in VSimulator5.exe.
• Deploy endpoint detection and response (EDR) rules for out-of-bounds write behavior.

Hunting:

• Search for V8 files with unusually large sizes or malformed headers.
• Analyze memory dumps for signs of heap corruption.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): None available (no public samples).
• Process Names: VSimulator5.exe, V8Parser.dll
• Network Indicators: None (local file-based exploitation).
• Registry Keys: None known.
• YARA Rule (see Detection Engineering): Detects malicious V8 files.

Detection Engineering

YARA Rule

rule CVE_2024_11801_Malicious_V8 {
    meta:
        description = "Detects malicious V8 files targeting CVE-2024-11801"
        author = "Valters IT"
        date = "2025-04-01"
        hash = "unknown"
    strings:
        $magic = { 56 38 46 49 4C 45 } // "V8FILE" magic bytes (example)
        $overflow = { 41 41 41 41 41 41 41 41 } // Pattern of A's
    condition:
        $magic at 0 and #overflow > 10
}

Sigma Rule

title: CVE-2024-11801 Exploitation Attempt
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects potential exploitation of CVE-2024-11801 via V8 file parsing
author: Valters IT
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: 'VSimulator5.exe'
        CommandLine|contains: '.v8'
    condition: selection
falsepositives:
    - Legitimate use of V8 files
level: high

Suricata Rule

alert tcp any any -> any any (msg:"CVE-2024-11801 V8 File Transfer"; flow:to_client; file.name:"*.v8"; file.size:>1000000; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate affected systems from untrusted networks.
2. Block V8 file attachments in email gateways.
3. Educate users not to open V8 files from untrusted sources.

Long-Term Fix:

• Await an official patch from Fuji Electric.
• If no patch is available, consider removing or disabling the V-Simulator 5 component.

Workarounds:

• Use application whitelisting to prevent execution of VSimulator5.exe unless necessary.
• Deploy memory protection tools (e.g., EMET, Windows Defender Exploit Guard).

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert