In late 2022, Siemens released a security advisory for several of its industrial software products, disclosing a critical vulnerability labeled CVE-2022-39136. This flaw found in JT2Go (all versions before V14.1..4) and Teamcenter Visualization (various versions, see below) allows remote code execution through a heap-based buffer overflow when the program opens specially crafted TIF (TIFF) files.

This post is written in plain English and breaks down what this vulnerability means, how an exploit might work, and how you can stay protected.

Teamcenter Visualization V14.1: All versions before V14.1..4

Note: Siemens fixed the issue in updates for these products. If you haven’t upgraded, you remain at risk.

Understanding the Vulnerability

The root cause is a fixed-length heap-based buffer overflow in the way the software parses TIF (TIFF) image files.

What Is a Heap-Based Buffer Overflow?

When a program reads more data into a buffer (a chunk of memory) than it can hold, the extra data overwrites adjacent memory. On the *heap*, where dynamic memory allocation occurs, this can corrupt data or control structures. Attackers can carefully craft input files so that this overflow can be controlled, potentially leading to arbitrary code execution.

Simplified Example

Suppose the application reads a TIF file and expects no more than 512 bytes for a tag, but the TIF file actually contains 1024 bytes for a tag. The program copies all 1024 bytes into a 512-byte buffer, causing an overflow.

void parse_tag(char* data){
    char buffer[512];
    memcpy(buffer, data, 1024); // No length check!
}

A malicious file causes memcpy to overwrite important memory. With careful construction, this can let an attacker run arbitrary code.

1. The Entry Point

Attackers send or place a specially crafted TIF file. If the victim opens this file in JT2Go or Teamcenter Visualization, the application triggers the bug and overflows the buffer on the heap.

Proof of Concept & Code Snippet

A basic TIF file crafted for buffer overflow could be made with a script. Here's a Python snippet to create a rudimentary oversized TIF header exploiting a length miscalculation.

# Example: Creating an oversized TIFF tag for exploitation
with open("exploit.tif", "wb") as f:
    # Standard TIFF header for little-endian
    f.write(b"II*\x00")
    # Fake IFD offset
    f.write(b"\x08\x00\x00\x00")
    # Number of directory entries
    f.write(b"\x01\x00")
    # Directory entry with an absurdly large count for the value
    f.write(b"\x01\x01")          # Tag
    f.write(b"\x04\x00")          # Type (long)
    f.write(b"\xff\xff\xff\x7f")  # Count: x7fffffff (very large)
    f.write(b"\x00\x00\x00\x00")  # Value offset
    # Next IFD offset
    f.write(b"\x00\x00\x00\x00")

*This “TIFF” isn’t fully valid, but demonstrates the concept: the count field is set absurdly high. By customizing the data structure and payload, a real-world exploit can be built. For ethical reasons, a full weaponized sample isn’t provided here.*

How To Tell If You're Vulnerable

- Check your versions: Use Help > About to confirm which version you have. If it’s older than the fixed release, you need to upgrade.
- Monitor for strange TIF files: Unusual or out-of-place files arriving by email or on shared drives should be investigated.

- Upgrade Immediately: Download and install the latest patched versions from Siemens

- JT2Go Download page
   - Teamcenter Visualization Download page

Restrict File Open: Only open TIF files from trusted sources.

- Network Segmentation: Limit access to vulnerable applications, especially on machines exposed to internet or shared environments.

User Awareness: Train staff to avoid opening unfamiliar files.

- Monitor Logs: Watch for application crashes or exceptions related to TIF files, which could signal exploitation attempts.

Siemens Security Advisory:

SSA-256124: Vulnerabilities in Teamcenter Visualization and JT2Go
- MITRE CVE Database: CVE-2022-39136
- NIST National Vulnerability Database: CVE-2022-39136
- TIFF File Format Specification

Conclusion

CVE-2022-39136 is a stark reminder that old file formats and trusted tools can hide new dangers. If you rely on Siemens visualization products, updating now is the best way to keep your systems and intellectual property safe.

*Always use caution when handling files from unknown or untrusted sources, and watch for updates from software vendors.*


*Exclusive article for educational awareness. For defensive use only. Do not use this information for unauthorized access or malicious activity.*

Timeline

Published on: 11/08/2022 11:15:00 UTC
Last modified on: 11/08/2022 16:30:00 UTC