Vulnerability identifier: #VU71302

Vulnerability risk: Medium

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2022-40267

CWE-ID: CWE-337

Exploitation vector: Network

Exploit availability: Yes

Vulnerable software:
MELSEC iQ-F FX5U
Hardware solutions / Routers & switches, VoIP, GSM, etc
MELSEC iQ-F FX5UC
Hardware solutions / Routers & switches, VoIP, GSM, etc
MELSEC iQ-F FX5UC-32MT/DS-TS
Hardware solutions / Routers & switches, VoIP, GSM, etc
MELSEC iQ-F FX5UC-32MT/DSS-TS
Hardware solutions / Routers & switches, VoIP, GSM, etc
MELSEC iQ-F FX5UC-32MR/DS-TS
Hardware solutions / Routers & switches, VoIP, GSM, etc
MELSEC iQ-R 00 CPU
Hardware solutions / Firmware
MELSEC iQ-R 01 CPU
Hardware solutions / Firmware
MELSEC iQ-R 02 CPU
Hardware solutions / Firmware
MELSEC iQ-R 04 (EN) CPU
Hardware solutions / Firmware
MELSEC iQ-R 08 (EN) CPU
Hardware solutions / Firmware
MELSEC iQ-R 16 (EN) CPU
Hardware solutions / Firmware
MELSEC iQ-R 32 (EN) CPU
Hardware solutions / Firmware
MELSEC iQ-R 120 (EN) CPU
Hardware solutions / Firmware

Vendor: Mitsubishi Electric

Description

The vulnerability allows a remote attacker to compromise the system.

The vulnerability exists due to predictable seed in the pseudo-random number generator within the WEB server function. A remote attacker can bypass authorization on the target system.

This vulnerability affects the following products:

• MELSEC iQ-F Series with serial number 17X**** or later:  
  • FX5U-xMy/z x=32,64,80, y=T,R, z=ES,DS,ESS,DSS: Versions 1.280 and prior 
  • FX5UC-xMy/z x=32,64,96 y=T, z=D,DSS: Versions 1.280 and prior 
• MELSEC iQ-F Series with serial number 179**** and prior:  
  • FX5U-xMy/z x=32,64,80, y=T,R, z=ES,DS,ESS,DSS: Versions 1.074 and prior 
  • FX5UC-xMy/z x=32,64,96 y=T, z=D,DSS: Versions 1.074 and prior 
• MELSEC iQ-F Series FX5UC-32MT/DS-TS, FX5UC-32MT/DSS-TS, FX5UC-32MR/DS-TS: Versions 1.280 and prior 
• MELSEC iQ-R Series R00/01/02CPU: All versions 
• MELSEC iQ-R Series R04/08/16/32/ 120(EN)CPU: All versions 

Mitigation
Install updates from vendor's website.

Vulnerable software versions

MELSEC iQ-F FX5U: 1.074 - 1.280

MELSEC iQ-F FX5UC: 1.074 - 1.280

MELSEC iQ-F FX5UC-32MT/DS-TS: 1.280

MELSEC iQ-F FX5UC-32MT/DSS-TS: 1.280

MELSEC iQ-F FX5UC-32MR/DS-TS: 1.280

MELSEC iQ-R 00 CPU: All versions

MELSEC iQ-R 01 CPU: All versions

MELSEC iQ-R 02 CPU: All versions

MELSEC iQ-R 04 (EN) CPU: All versions

MELSEC iQ-R 08 (EN) CPU: All versions

MELSEC iQ-R 16 (EN) CPU: All versions

MELSEC iQ-R 32 (EN) CPU: All versions

MELSEC iQ-R 120 (EN) CPU: All versions

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External links
http://ics-cert.us-cert.gov/advisories/icsa-23-017-02

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.