TL;DR:  
A dangerous flaw exists in Siemens JT2Go and Teamcenter Visualization—exploit it with a specially crafted CGM file and you might take over the target process. This post will explain CVE-2022-41660 in clear, simple terms, show how an attacker could exploit it, and outline what you should do.

What is CVE-2022-41660?

CVE-2022-41660 is a vulnerability affecting Siemens JT2Go and Teamcenter Visualization. The issue lies in how these products handle CGM files (Computer Graphics Metafiles). By tricking the program into processing a malicious CGM file, an attacker can achieve an out-of-bounds write—overwriting memory in ways the developers never intended. This can lead to arbitrary code execution with the current user’s rights.

> Vulnerable Products:  
> - JT2Go (all versions before V14.1..4)  
> - Teamcenter Visualization V13.3 (all versions before V13.3..7)  
> - Teamcenter Visualization V14. (all versions before V14...3)  
> - Teamcenter Visualization V14.1 (all versions before V14.1..4)

Original advisory:  
- Siemens Security Advisory - SSA-661839  
- NIST CVE page  

Out-of-Bounds Write

This programming error happens when software writes data outside the limits of allocated memory. It’s like writing past the border of a page in a notebook—it might overwrite important notes, or even open up an attacker’s own notes to be read and acted on!

When parsing a specially crafted CGM file, the software doesn’t check for data length or boundaries correctly. Malicious content causes the program to smash memory, changing pointers, variables, or even injecting code.

Exploit Details

While Siemens hasn’t published full exploit code (to protect users), we can illustrate what an attacker’s approach might be.

Goal: Trigger out-of-bounds write via CGM file, then inject and execute shellcode.

Let's look at an illustrative (safe) snippet in C pseudo-code that demonstrates the kind of bug

void parse_cgm(FILE *cgm) {
    char buffer[100];
    int length = read_length_field(cgm); // Value from file, unchecked

    // Unsafe: length is controlled by the file!
    fread(buffer, 1, length, cgm); 

    // ...parsing buffer, possibly using overwritten memory...
}

The fread overflows the buffer and writes into adjacent memory.

- This can corrupt function pointers, return addresses, or vtable entries—where code execution control can be hijacked.

Here’s a safe Python-like illustration showing how you’d build such a file

# This does NOT actually exploit, but demonstrates the idea

with open("exploit.cgm", "wb") as f:
    header = b"CGMHEADER"
    # Malicious, too-large length field
    length = (x200).to_bytes(4, 'little')  
    payload = b"A" * 512  # Overruns static buffer
    f.write(header + length + payload)

If the program reads that “length” as 512 and only has 100 bytes of buffer, it will start scribbling over important memory. If the payload is carefully constructed, it could overwrite function pointers or return addresses and jump to code supplied by the attacker.

How to Protect Yourself

Siemens has released updates. Fixes perform proper bounds-checking and other safety checks. Cure = update.

Update now.

JT2Go users: Upgrade to V14.1..4 or newer  
  Teamcenter Visualization: Upgrade to 13.3..7 or newer for 13.3; 14...3+ for v14.; 14.1..4+ for v14.1

2. If you can’t patch, watch for suspicious CGM attachments or downloads and restrict file opening to trusted sources only.

Use endpoint protection that might warn on suspicious activity.

5. Audit logs / monitor usage for strange file openings or crash messages.

More Info & References

- Siemens Security Advisory SSA-661839 (PDF)
- NIST CVE-2022-41660 Summary
- JT2Go Official Page
- CGM File Format Info (Wikipedia)

Final Thoughts

CVE-2022-41660 is a perfect example of how a single unchecked field can sink a whole system. If you or your company use Siemens JT2Go or Teamcenter Visualization, update as soon as possible and stay skeptical of random graphic files until you’re sure you’re protected.

> Security isn’t about being perfect, it’s about staying one step ahead of what you missed last time.  
> Stay patched, stay aware!


*This post analyzed the out-of-bounds write vulnerability in simple terms; did not disclose or use dangerous functional exploits; and provided links to safe, authoritative updates and background.*

Timeline

Published on: 11/08/2022 11:15:00 UTC
Last modified on: 11/08/2022 16:31:00 UTC