CVE-2020-12739

A denial-of-service vulnerability in the Fanuc i Series CNC (0i-MD and 0i Mate-MD) could allow an unauthenticated, remote attacker to cause an affected CNC to become inaccessible to other devices.

Published: 2020-08-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-12739 is rated Moderate Risk (49.5/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.95%). EPSS rose +1.15% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-12739

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.80% 1.95% +1.15%
2 2025-03-30 1.12% 0.80% -0.32%
3 2025-03-29 — 1.12% —

Full EPSS history (15 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-12739

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2020-12739

Affected software / configurations for CVE-2020-12739

Vendor Product Version Raw CPE
fanuc series_30i_firmware — cpe:2.3:o:fanuc:series_30i_firmware:-:*:*:*:*:*:*:*
fanuc series_31i_firmware — cpe:2.3:o:fanuc:series_31i_firmware:-:*:*:*:*:*:*:*
fanuc series_32i-b_plus_firmware — cpe:2.3:o:fanuc:series_32i-b_plus_firmware:-:*:*:*:*:*:*:*
fanuc series_35i-b_firmware — cpe:2.3:o:fanuc:series_35i-b_firmware:-:*:*:*:*:*:*:*
fanuc power_motion_i-model_a_firmware — cpe:2.3:o:fanuc:power_motion_i-model_a_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-model_f_plus_firmware — cpe:2.3:o:fanuc:series_0i-model_f_plus_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-model_f_firmware — cpe:2.3:o:fanuc:series_0i-model_f_firmware:-:*:*:*:*:*:*:*
fanuc series_32i-model_a_firmware — cpe:2.3:o:fanuc:series_32i-model_a_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-model_d_firmware — cpe:2.3:o:fanuc:series_0i-model_d_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-mate_d_firmware — cpe:2.3:o:fanuc:series_0i-mate_d_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-model_c_firmware — cpe:2.3:o:fanuc:series_0i-model_c_firmware:-:*:*:*:*:*:*:*
fanuc series_16i_firmware — cpe:2.3:o:fanuc:series_16i_firmware:-:*:*:*:*:*:*:*
fanuc series_18i_firmware — cpe:2.3:o:fanuc:series_18i_firmware:-:*:*:*:*:*:*:*
fanuc series_21i-model_b_firmware — cpe:2.3:o:fanuc:series_21i-model_b_firmware:-:*:*:*:*:*:*:*
fanuc series_0i-model_b_firmware — cpe:2.3:o:fanuc:series_0i-model_b_firmware:-:*:*:*:*:*:*:*
fanuc series_18i-wb_firmware — cpe:2.3:o:fanuc:series_18i-wb_firmware:-:*:*:*:*:*:*:*

References for CVE-2020-12739

cvelogic Threat Intelligence