Rockwell Automation Modbus TCP AOI Server Could Leak Sensitive Information

published 2023-03-17 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-12132

cvss: 5.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

Rockwell Automation Modbus TCP Server AOI prior to 2.04.00 is vulnerable to an unauthorized user sending a malformed message that could cause the controller to respond with a copy of the most recent response to the last valid request. If exploited, an unauthorized user could read the connected device’s Modbus TCP Server AOI information.

Patch / fix

fixed in 1

rockwellautomation modbus_tcp_server_add_on_instructions 2.04.00

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-23-075-07 updated 2023-03-31 cvss 5.3

Rockwell Automation Modbus TCP AOI Server

Rockwell Automation Modbus TCP Server AOI 2.00, 2.03
affected: vendor fix rockwellautomation.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 20 mo ago (2025-02-26)

Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.3	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected products

Rockwell Automation Modbus TCP Server Add On Instructions

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

rockwellautomation.custhelp.com /app/answers/answer_view/a_id/1138766
permissions-required, vendor-advisory

Sources

CVE List CVE-2023-0027
NVD CVE-2023-0027

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary