What is CVE-2023-28657?

CVE-2023-28657 is a high-severity vulnerability in Contec Conprosys Hmi System, classified under Missing Authorization. CVSS score: 8.8/10. Published 2023-06-01.

How severe is CVE-2023-28657?

High severity. CVSS v3 base score is 8.8 out of 10.

Auth bypass in Contec Conprosys Hmi System

CVE-2023-28657

Improper access control vulnerability exists in CONPROSYS HMI System (CHS) versions prior to 3.5.3. A user of the PC where the affected product is installed may gain an administrative privilege. As a result, information regarding the product may be obtained and/or altered by the user.

Vulnerability class: Broken Access Control

Published 2023-06-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (52.6th percentile), scored 2026-10-21.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000

Affected products

Contec Conprosys Hmi System
Contec Co., Ltd. Conprosys Hmi System (Chs) — versions versions prior to 3.5.3

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

www.contec.com/api/downloadlogger (Vendor Advisory)
www.contec.com/jp/api/downloadlogger (Vendor Advisory)
jvn.jp/en/vu/JVNVU93372935/ (Third Party Advisory)

Frequently asked questions

What is CVE-2023-28657?: CVE-2023-28657 is a high-severity vulnerability in Contec Conprosys Hmi System, classified under Missing Authorization. CVSS score: 8.8/10. Published 2023-06-01.
How severe is CVE-2023-28657?: High severity. CVSS v3 base score is 8.8 out of 10.