What is CVE-2023-0811?

CVE-2023-0811 is a critical-severity vulnerability in Omron Cj1m Sysmac Cj-Series, classified under Improper Access Control. CVSS score: 9.1/10. Published 2023-03-16.

How severe is CVE-2023-0811?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Is CVE-2023-0811 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Omron Cj1m Sysmac Cj-Series

CVE-2023-0811

Omron CJ1M unit v4.0 and prior has improper access controls on the memory region where the UM password is stored. If an adversary issues a PROGRAM AREA WRITE command to a specific memory region, they could overwrite the password. This may lead to disabling UM protections or setting a non-ASCII password (non-keyboard characters) and preventing an engineer from viewing or modifying the user program.

Published 2023-03-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (47.9th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 48th percentile — 47.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Omron Cj1m Sysmac Cj-Series — versions All versions
Omron Cj1m Sysmac Cp-Series — versions All versions
Omron Cj1m Sysmac Cs-Series — versions All versions
Omron Sysmac Cj2h-Cpu64
Omron Sysmac Cj2h-Cpu64-Eip
Omron Sysmac Cj2h-Cpu64-Eip Firmware
Omron Sysmac Cj2h-Cpu64 Firmware
Omron Sysmac Cj2h-Cpu65
Omron Sysmac Cj2h-Cpu65-Eip
Omron Sysmac Cj2h-Cpu65-Eip Firmware

Weakness classification (CWE)

CWE-284 — Improper Access Control

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

www.cisa.gov/news-events/ics-advisories/icsa-23-073-01 (US Government Resource, Third Party Advisory)
www.ia.omron.com/product/vulnerability/OMSR-2023-001_en.pdf (Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2023-0811?: CVE-2023-0811 is a critical-severity vulnerability in Omron Cj1m Sysmac Cj-Series, classified under Improper Access Control. CVSS score: 9.1/10. Published 2023-03-16.
How severe is CVE-2023-0811?: Critical severity. CVSS v3 base score is 9.1 out of 10.
Is CVE-2023-0811 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.