1763 L16bwa FirmwareOperating system · Rockwellautomation

CVE-2017-7924

HIGH · 7.5 CVSS v3.0 Published 2017-09-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is an improper input validation vulnerability in Rockwell Automation MicroLogix 1100 controllers (models 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, and 1763-L16DWD). A remote, unauthenticated attacker can send a specially crafted PCCC (Programmable Controller Communication Commands) packet that causes the controller to enter a Denial of Service condition.

MitigationIsolate affected controllers on a restricted network segment and apply any available vendor firmware updates; implement firewall rules to limit PCCC traffic to authorized sources only.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
1763 L16bwa FirmwareOperating system
Affected:all versions
1763 L16awa FirmwareOperating system
Affected:all versions
1763 L16bbb FirmwareOperating system
Affected:all versions
1763 L16dwd FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the controller model
    Locate the model number label on the physical MicroLogix 1100 controller or query the controller's firmware information through RSLogix/Studio 5000 or the embedded web server (if available)
    Affected if The model number is 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, or 1763-L16DWD (any firmware version)
  2. Verify PCCC protocol is enabled
    Check if the controller has PCCC/EtherNet/IP communication enabled. This can be done by reviewing the controller's communication configuration in RSLogix/Studio 5000 or by scanning the controller's IP address on port 44818 (EtherNet/IP)
    Affected if PCCC over Ethernet is enabled and responding on the network
  3. Check network exposure of PCCC port
    Scan the controller's IP address for open port 44818 (EtherNet/IP PCCC). Use a network scanner or `nmap -p 44818 <controller_ip>` to determine if the port is accessible
    Affected if Port 44818 is open and reachable from network segments accessible to unauthorized users
  4. Assess network segmentation
    Review the network topology and VLAN configuration to determine if the controller is isolated on a restricted network segment or if it shares network space with untrusted systems
    Affected if The controller is on an unisolated network segment without physical or logical isolation from untrusted hosts

You are affected if you have any of the four MicroLogix 1100 model variants (1763-L16BWA, 1763-L16AWA, 1763-L16BBB, 1763-L16DWD) with PCCC enabled and accessible from network paths that could be reached by an unauthenticated remote attacker.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Isolate affected controllers on a restricted network segment and apply any available vendor firmware updates; implement firewall rules to limit PCCC traffic to authorized sources only.

Fix this in 1763 L16bwa Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,880
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-7924 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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