# What is CVE-2016-9343?

> CVE-2016-9343 is a critical-severity flaw (CVSS 10.0) in Softlogix 5800 Controller Firmware from Rockwellautomation, published on 13 February 2017. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 10%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2016-9343

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 55 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** Critical (CVSS 10.0 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 10% (latest exploit-likelihood forecast)
- **Published:** 13 February 2017
- **Record last updated:** 20 April 2025
- **Main product:** Softlogix 5800 Controller Firmware from Rockwellautomation
- **Affected products:** 32

## What is CVE-2016-9343? In plain terms

It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### The official description

An issue was discovered in Rockwell Automation Logix5000 Programmable Automation Controller FRN 16.00 through 21.00 (excluding all firmware versions prior to FRN 16.00, which are not affected). By sending malformed common industrial protocol (CIP) packet, an attacker may be able to overflow a stack-based buffer and execute code on the controller or initiate a nonrecoverable fault resulting in a denial of service.

### What kind of flaw is it?

- CWE-787: Out-of-bounds Write

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Easy: no special conditions
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Is CVE-2016-9343 being exploited? Not that we know of

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 10%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 10%, 10%, 10%, 10%, 10%, 10%, 10%.

### Timeline

- 13 February 2017: Published
- 20 April 2025: Record last updated
- 16 June 2026: Exploit likelihood jumped

### How Precursor Intelligence ranks it

CVE-2016-9343 scores **55 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2016-9343?

The published record lists 32 products.

- [Softlogix 5800 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/softlogix_5800_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 18.00, 19.00, 20.00, 21.00
- [1768 Compactlogix L4x Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1768_compactlogix_l4x_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 16.020, 16.025, 17.00, 18.00, 19.00, 20.00, 20.011, 20.016
- [1769 Compactlogix L3x Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_l3x_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 16.020, 16.023, 17.00, 18.00, 19.00, 20.00, 20.010, 20.013
- [Controllogix 5560 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5560_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 16.020, 16.022, 17.00, 18.00, 19.00, 20.00, 20.010, 20.013
- [Guardlogix 5570 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/guardlogix_5570_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 17.00, 18.00, 19.00, 20.00, 20.010, 20.017, 21.00
- [1769 Compactlogix L23x Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_l23x_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 17.00, 18.00, 19.00, 20.00, 20.010, 20.013
- [1768 Compact Guardlogix L4xs Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1768_compact_guardlogix_l4xs_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 18.00, 19.00, 20.00, 20.011, 20.013
- [Controllogix 5560 Redundant Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5560_redundant_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 19.00, 20.00, 20.050, 20.055
- [Controllogix 5570 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5570_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 18.00, 19.00, 20.010, 20.013, 21.00
- [1769 Compactlogix 5370 L1 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l1_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 20.00, 20.010, 20.013, 21.00
- [1769 Compactlogix 5370 L2 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l2_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 20.00, 20.010, 20.013, 21.00
- [1769 Compactlogix 5370 L3 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l3_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 20.00, 20.010, 20.013, 21.00
- [Controllogix 5570 Redundant Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5570_redundant_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 20.00, 20.050, 20.055, 21.00
- [Rslogix Emulate 5000 Firmware](https://www.precursorintelligence.com/product/rockwellautomation/rslogix_emulate_5000_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 18.00, 19.00, 20.00, 21.00
- [Controllogix L55 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_l55_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00, 16.020, 16.022
- [1768 Compact Guardlogix L4xs Controller](https://www.precursorintelligence.com/product/rockwellautomation/1768_compact_guardlogix_l4xs_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1768 Compactlogix L4x Controller](https://www.precursorintelligence.com/product/rockwellautomation/1768_compactlogix_l4x_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1769 Compactlogix 5370 L1 Controller](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l1_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1769 Compactlogix 5370 L2 Controller](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l2_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1769 Compactlogix 5370 L3 Controller](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_5370_l3_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1769 Compactlogix L23x Controller](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_l23x_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [1769 Compactlogix L3x Controller](https://www.precursorintelligence.com/product/rockwellautomation/1769_compactlogix_l3x_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Controllogix 5560 Controller](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5560_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Controllogix 5560 Redundant Controller](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5560_redundant_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Controllogix 5570 Controller](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5570_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Controllogix 5570 Redundant Controller](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_5570_redundant_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Controllogix L55 Controller](https://www.precursorintelligence.com/product/rockwellautomation/controllogix_l55_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Flexlogix L34 Controller](https://www.precursorintelligence.com/product/rockwellautomation/flexlogix_l34_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Flexlogix L34 Controller Firmware](https://www.precursorintelligence.com/product/rockwellautomation/flexlogix_l34_controller_firmware) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Operating system): 16.00
- [Guardlogix 5570 Controller](https://www.precursorintelligence.com/product/rockwellautomation/guardlogix_5570_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Rslogix Emulate 5000](https://www.precursorintelligence.com/product/rockwellautomation/rslogix_emulate_5000) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified
- [Softlogix 5800 Controller](https://www.precursorintelligence.com/product/rockwellautomation/softlogix_5800_controller) by [Rockwellautomation](https://www.precursorintelligence.com/vendors/rockwellautomation) (Hardware): version not specified

## How do I fix CVE-2016-9343?

1. **Check whether you run it.** Compare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
2. **Apply the vendor’s fix.** Install the latest update from the vendor. The references list where the vendor has published details.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.

### References

- [securityfocus.com](http://www.securityfocus.com/bid/95304) (Third-party advisory, Vulnerability database)
- [ics-cert.us-cert.gov](https://ics-cert.us-cert.gov/advisories/ICSA-16-343-05) (Third-party advisory, Government resource)

## Questions

### What is CVE-2016-9343?

CVE-2016-9343 is a critical-severity flaw in Softlogix 5800 Controller Firmware from Rockwellautomation, published on 13 February 2017. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2016-9343?

It scores 10.0 out of 10 on the CVSS severity scale, which is critical. Our risk score for CVE-2016-9343 is 55 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2016-9343 being exploited?

It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 10%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2016-9343 affect?

For Softlogix 5800 Controller Firmware from Rockwellautomation: 18.00, 19.00, 20.00, 21.00. The record lists 32 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2016-9343?

Install the update the vendor names in its advisory. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.

## Does CVE-2016-9343 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

Start free (no card, nothing to install): https://www.precursorintelligence.com/register
Book a demo: https://www.precursorintelligence.com/contact