What is CVE-2018-14821?

CVE-2018-14821 is a high-severity vulnerability in Rockwell Automation Rslinx Classic, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2018-09-20.

How severe is CVE-2018-14821?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Rockwell Automation Rslinx Classic

CVE-2018-14821

Rockwell Automation RSLinx Classic Versions 4.00.01 and prior. This vulnerability may allow a remote, unauthenticated threat actor to intentionally send a malformed CIP packet to Port 44818, causing the RSLinx Classic application to terminate. The user will need to manually restart the software to regain functionality.

Vulnerability class: Buffer Overflow

Published 2018-09-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.045 (91.5th percentile), scored 2026-10-29.

Low probability of exploitation in the next 30 days, but still tracked. 91st percentile — 91.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.045 · newest: 0.045 · change: 0.000

Affected products

Rockwell Automation Rslinx Classic — versions 4.00.01 and prior
Rockwellautomation Rslinx

Weakness classification (CWE)

References

ics-cert.us-cert.gov/advisories/ICSA-18-263-02 (US Government Resource, Third Party Advisory)
www.tenable.com/security/research/tra-2018-26 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2018-14821?: CVE-2018-14821 is a high-severity vulnerability in Rockwell Automation Rslinx Classic, classified under Heap-based Buffer Overflow. CVSS score: 7.5/10. Published 2018-09-20.
How severe is CVE-2018-14821?: High severity. CVSS v3 base score is 7.5 out of 10.