Mitsubishi Electric MELSEC iQ-R Series Exposure of Sensitive Information to an Unauthorized Actor (CVE-2021-20594)

high Tenable OT Security Plugin ID 500576

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Mitsubishi Electric MELSEC iQ-R series CPU modules (R08/16/32/120SFCPU all versions, R08/16/32/120PSFCPU all versions) allows a remote unauthenticated attacker to acquire legitimate user names registered in the module via brute-force attack on user names.

This plugin only works with Tenable.ot. Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Users of the affected products and versions may take measures through mitigations and workarounds. Mitsubishi Electric has released the fixed versions for CVE-2021-20594 and CVE-2021-20597 as shown below, but updating the product to the fixed version is not available.

- MELSEC iQ-R series Safety CPU R08/16/32/120SFCPU:Firmware versions "27" or later
- MELSEC iQ-R series SIL2 Process CPU R08/16/32/120PSFCPU:Firmware versions "12" or later

Mitsubishi Electric recommends users take the following mitigation measures to minimize the risk of exploiting these vulnerabilities:

- Use a firewall or virtual private network (VPN), etc. to prevent unauthorized access when Internet access is required.
- Use within a LAN and block access from untrusted networks and hosts through firewalls.
- Use the IP filter function to restrict the accessible IP addresses. MELSEC iQ-R Ethernet User's Manual (Application) 1.13 Security "IP filter"
- Register user information or change the password via USB. If you have already registered user information or changed the user's password via the network, change the password once via USB. This mitigation is applicable to CVE-2021-20597

Additional information about these vulnerabilities or Mitsubishi Electric's compensating control is available by contacting a Mitsubishi Electric representative.

Users should refer to Mitsubishi Electric advisories 2021-008,2021-009, and 2021-010 for further details.

Plugin Details

Severity: High

ID: 500576

Version: 1.12

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 9/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

CVSS Score Source: CVE-2021-20594

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:mitsubishielectric:r08psfcpu_firmware, cpe:/o:mitsubishielectric:r16sfcpu_firmware, cpe:/o:mitsubishielectric:r08sfcpu_firmware, cpe:/o:mitsubishielectric:r16psfcpu_firmware, cpe:/o:mitsubishielectric:r120sfcpu_firmware, cpe:/o:mitsubishielectric:r120psfcpu_firmware, cpe:/o:mitsubishielectric:r32sfcpu_firmware, cpe:/o:mitsubishielectric:r32psfcpu_firmware

Required KB Items: Tenable.ot/Mitsubishi

Exploit Ease: No known exploits are available

Patch Publication Date: 8/6/2021

Vulnerability Publication Date: 8/6/2021

Reference Information

CVE: CVE-2021-20594

CWE: 200

ICSA: 21-250-01

Detections

Analytics