Published:2020/07/31  Last Updated:2020/07/31

FANUC i Series CNC vulnerable to denial-of-service (DoS)


Fanuc i Series CNC contains a denial-of-service (DoS) vulnerability.

Products Affected

  • Embedded Ethernet 658M series
    • FANUC Series 30i/31i/32i-B Plus
    • FANUC Series 30i/31i/32i/35i-B
    • FANUC Power Motion i-MODEL A
  • Embedded Ethernet 658A series
    • FANUC Series 0i-MODEL F Plus
    • FANUC Series 0i-MODEL F
  • Embedded Ethernet 656E series
    • FANUC Series 30i/31i/32i-MODEL A
  • Embedded Ethernet 658E series
    • FANUC Series 0i-MODEL D
    • FANUC Series 0i-Mate D
  • Embedded Ethernet 656V series
    • FANUC Series 0i-MODEL C
  • Embedded Ethernet 656A series
    • FANUC Series 16i/18i/21i-MODEL B
    • FANUC Series 0i-MODEL B
  • Embedded Ethernet 656B series
    • FANUC Series 16i/18i-WB
For the details, refer to the information provided by the developer (Registered Users Only).


Fanuc i Series CNC provided by FANUC CORPORATION contains a denial-of-service (DoS) (CWE-400) vulnerability.


A remote attacker may cause a denial-of-service (DoS) condition and access to the other devices may be blocked.


Update the software or apply the patch
The developer states that the updates/patches are available.
For the details, refer to the information provided by the developer (Registered Users Only).

Apply workaround
Applying the following workaround may mitigate the impact of this vulnerability.

  • Set up Firewall and restrict access from the devices via network.

Vendor Status

Vendor Link
FANUC CORPORATION FANUC Member's Site (Registered Users Only)


JPCERT/CC Addendum

Vulnerability Analysis by JPCERT/CC

Base Score: 4.3
Attack Vector(AV) Physical (P) Local (L) Adjacent (A) Network (N)
Attack Complexity(AC) High (H) Low (L)
Privileges Required(PR) High (H) Low (L) None (N)
User Interaction(UI) Required (R) None (N)
Scope(S) Unchanged (U) Changed (C)
Confidentiality Impact(C) None (N) Low (L) High (H)
Integrity Impact(I) None (N) Low (L) High (H)
Availability Impact(A) None (N) Low (L) High (H)
Base Score: 3.3
Access Vector(AV) Local (L) Adjacent Network (A) Network (N)
Access Complexity(AC) High (H) Medium (M) Low (L)
Authentication(Au) Multiple (M) Single (S) None (N)
Confidentiality Impact(C) None (N) Partial (P) Complete (C)
Integrity Impact(I) None (N) Partial (P) Complete (C)
Availability Impact(A) None (N) Partial (P) Complete (C)


Industrial Control Security Laboratory of Qi An Xin Technology Group Inc. from China reported this vulnerability to IPA.
JPCERT/CC coordinated with the developer under Information Security Early Warning Partnership.

Other Information

JPCERT Reports
CERT Advisory
CPNI Advisory
CVE CVE-2020-12739
JVN iPedia JVNDB-2020-000050

Update History

Entered CVSS scores under the section [Vulnerability Analysis by JPCERT/CC]
Added information under [Credit] section and fixed CVE ID under [Other Information] section.