# CVE-2017-7924: Denial of service in Rockwell Automation MicroLogix 1100 Controllers

> A remote unauthenticated attacker can cause a denial of service on Rockwell Automation MicroLogix 1100 controllers by sending a specially crafted PCCC packet.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Sep 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-ch2w-m37v-83fq

## What is CVE-2017-7924?

CVE-2017-7924 is a high-severity denial of service vulnerability in Rockwell Automation MicroLogix 1100 Controllers, published on 20 Sep 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Improper Input Validation issue was discovered in Rockwell Automation MicroLogix 1100 controllers 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, and 1763-L16DWD. A remote, unauthenticated attacker could send a single, specially crafted Programmable Controller Communication Commands (PCCC) packet to the controller that could potentially cause the controller to enter a DoS condition.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-7924?

It affects 4 products.


Products: Rockwellautomation 1763-L16awa Firmware, Rockwellautomation 1763-L16bbb Firmware, Rockwellautomation 1763-L16bwa Firmware, Rockwellautomation 1763-L16dwd Firmware.

## How do I fix CVE-2017-7924?

No fix has been published for CVE-2017-7924 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-7924 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-7924 exists.

Public exploit code:

- DoS Exploitation of Allen-Bradley's Legacy Protocol (PCCC) (metasploit)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-7924 and fix it if it is affected.

What it is: CVE-2017-7924 is a high-severity denial of service vulnerability in Rockwell Automation MicroLogix 1100 Controllers, published on 20 Sep 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2017-7924 exists.

Affected product: Rockwell Automation MicroLogix 1100 Controllers. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2017-7924/ (Markdown: https://insights.sbomify.com/CVE-2017-7924/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-7924
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-7924
- OSV: https://osv.dev/vulnerability/CVE-2017-7924

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-7924/
Summaries are generated and may contain mistakes; the official description above is the record.