CVE-2022-41661 - Out-of-Bounds Read in JT2Go and Teamcenter Visualization—Attack Details and Exploit Guidance

In late 2022, a critical vulnerability identified as CVE-2022-41661 was found in several Siemens visualization and CAD products. This flaw specifically impacts:

Teamcenter Visualization V14.1 (all versions prior to V14.1..4)

The vulnerability lies in how these applications parse CGM (Computer Graphics Metafile) files, resulting in an out-of-bounds (OOB) read that can be exploited to execute arbitrary code with the permissions of the current user. This post demystifies CVE-2022-41661 and walks through a conceptual exploit, using simple language and referencing key resources.

What is an Out-Of-Bounds Read?

Software that works with files often reads structured data from those files. If a program tries to read data from outside the limits or boundaries of the allocated memory, it’s called an out-of-bounds read. This happens because the program either trusts file contents too much or does not check lengths properly.

In the case of JT2Go and Teamcenter Visualization, a specially-crafted CGM file can force the application to read memory it shouldn’t. Depending on what’s read, a successful attack might leak sensitive data, make the program crash, or, more dangerously, let an attacker execute code.

Here’s a quick table of affected versions

| Product                        | Affected Versions        | Fixed Version   |
|---------------------------------|-------------------------|-----------------|
| JT2Go                          | All < V14.1..4         | V14.1..4       |
| Teamcenter Visualization V13.3  | All < V13.3..7         | V13.3..7       |
| Teamcenter Visualization V14.  | All < V14...3         | V14...3       |
| Teamcenter Visualization V14.1  | All < V14.1..4         | V14.1..4       |

How Does the Attack Work?

1. Craft a Malicious CGM File: An attacker creates a CGM file with malicious payloads. These payloads are carefully designed so that, when processed, the program reads past allowed memory boundaries.

2. Trigger the Vulnerability: The victim is tricked into opening the file with a vulnerable version of JT2Go or Teamcenter Visualization.

3. Arbitrary Code Execution: With precise crafting, the attacker’s data can get executed—potentially installing malware or giving control over the victim’s computer.

Code Example: Simulating the Flaw

Below is Python pseudocode emulating how a faulty parser might fail. This is for educational purposes only and is a safe simulation.

def parse_cgm(file_bytes):
    record_count = file_bytes[]  # Should check file length here
    pointer = 1
    for _ in range(record_count):
        # Vulnerability: does not check if pointer + 4 > len(file_bytes)
        record_size = int.from_bytes(file_bytes[pointer:pointer+4], 'little')
        pointer += 4
        # Imagine processing continues here...

# Malicious file: declares 50 records, but file only has bytes for 1
malicious_bytes = bytearray([50]) + bytearray([x04, x00, x00, x00])

try:
    parse_cgm(malicious_bytes)
except Exception as e:
    print(f"Error hit: {e}")

The issue: The parser trusts the "record count" field and tries to read way past the file’s actual contents.

Practical Exploit

While Siemens and others have not published public exploits for safety, the general exploit technique centers on heap grooming via the CGM file. An attacker fills a CGM file with fields that precisely overflow into attacker-controlled memory. Modern protections like ASLR and DEP make real exploitation harder, but not impossible if paired with other bugs like infoleaks.

Step 1: Attacker emails an HR employee a “HR_chart.cgm” diagram.

- Step 2: Employee opens the file in JT2Go/Teamcenter Visualization.

Update Now! Patch all affected products to the latest versions ASAP

- Download JT2Go Updates
  - Teamcenter Visualization Patches (requires login)

2. Block Unknown CGM Files: Restrict email/file sharing of CGM file attachments.

References and Further Reading

- Siemens Security Advisory SSA-825722 (PDF)
- National Vulnerability Database: CVE-2022-41661
- JT2Go Official Site

Final Thoughts

CVE-2022-41661 shows us that even non-code files like graphics can be a threat if untrusted content is handled insecurely. Always keep your software updated, and never underestimate the power of carefully crafted files.

If you’re running any of the affected Siemens visualization tools, patch today—waiting could mean your next graphics file is more than meets the eye.

Timeline

Published on: 11/08/2022 11:15:00 UTC
Last modified on: 11/08/2022 16:29:00 UTC