CVE-2021-20595

Improper Restriction of XML External Entity Reference vulnerability in Mitsubishi Electric Air Conditioning System/Centralized Controllers (G-50A Ver.3.35 and prior, GB-50A Ver.3.35 and prior, GB-24A Ver.9.11 and prior, AG-150A-A Ver.3.20 and prior, AG-150A-J Ver.3.20 and prior, GB-50ADA-A Ver.3.20 and prior, GB-50ADA-J Ver.3.20 and prior, EB-50GU-A Ver 7.09 and prior, EB-50GU-J Ver 7.09 and prior, AE-200A Ver 7.93 and prior, AE-200E Ver 7.93 and prior, AE-50A Ver 7.93 and prior, AE-50E Ver 7.93 and prior, EW-50A Ver 7.93 and prior, EW-50E Ver 7.93 and prior, TE-200A Ver 7.93 and prior, TE-50A Ver 7.93 and prior, TW-50A Ver 7.93 and prior, CMS-RMD-J Ver.1.30 and prior), Air Conditioning System/Expansion Controllers (PAC-YG50ECA Ver.2.20 and prior) and Air Conditioning System/BM adapter(BAC-HD150 Ver.2.21 and prior) allows a remote unauthenticated attacker to disclose some of data in the air conditioning system or cause a DoS condition by sending specially crafted packets.

Published: 2021-07-13 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20595 is rated Moderate Risk (60.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.78%). EPSS rose +1.63% 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-2021-20595

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 0.15% 1.78% +1.63%
2 2025-03-30 0.39% 0.15% -0.23%
3 2025-03-29 — 0.39% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20595

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H 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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 4.2 [email protected]
8.5 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:N/A:C 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:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 7.8 [email protected]

Weakness enumeration for CVE-2021-20595

Affected software / configurations for CVE-2021-20595

Vendor Product Version Raw CPE
mitsubishi g-50a_firmware >= 2.50, <= 3.35 cpe:2.3:o:mitsubishi:g-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi gb-50a_firmware >= 2.50, <= 3.35 cpe:2.3:o:mitsubishi:gb-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi ag-150a-a_firmware <= 3.20 cpe:2.3:o:mitsubishi:ag-150a-a_firmware:*:*:*:*:*:*:*:*
mitsubishi ag-150a-j_firmware <= 3.20 cpe:2.3:o:mitsubishi:ag-150a-j_firmware:*:*:*:*:*:*:*:*
mitsubishi gb-50ada-a_firmware <= 3.20 cpe:2.3:o:mitsubishi:gb-50ada-a_firmware:*:*:*:*:*:*:*:*
mitsubishi gb-50ada-j_firmware <= 3.20 cpe:2.3:o:mitsubishi:gb-50ada-j_firmware:*:*:*:*:*:*:*:*
mitsubishi eb-50gu-a_firmware <= 7.09 cpe:2.3:o:mitsubishi:eb-50gu-a_firmware:*:*:*:*:*:*:*:*
mitsubishi eb-50gu-j_firmware <= 7.09 cpe:2.3:o:mitsubishi:eb-50gu-j_firmware:*:*:*:*:*:*:*:*
mitsubishi ae-200a_firmware <= 7.93 cpe:2.3:o:mitsubishi:ae-200a_firmware:*:*:*:*:*:*:*:*
mitsubishi ae-200e_firmware <= 7.93 cpe:2.3:o:mitsubishi:ae-200e_firmware:*:*:*:*:*:*:*:*
mitsubishi ae-50a_firmware <= 7.93 cpe:2.3:o:mitsubishi:ae-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi ae-50e_firmware <= 7.93 cpe:2.3:o:mitsubishi:ae-50e_firmware:*:*:*:*:*:*:*:*
mitsubishi ew-50a_firmware <= 7.93 cpe:2.3:o:mitsubishi:ew-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi ew-50e_firmware <= 7.93 cpe:2.3:o:mitsubishi:ew-50e_firmware:*:*:*:*:*:*:*:*
mitsubishi te-200a_firmware <= 7.93 cpe:2.3:o:mitsubishi:te-200a_firmware:*:*:*:*:*:*:*:*
mitsubishi te-50a_firmware <= 7.93 cpe:2.3:o:mitsubishi:te-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi tw-50a_firmware <= 7.93 cpe:2.3:o:mitsubishi:tw-50a_firmware:*:*:*:*:*:*:*:*
mitsubishi cms-rmd-j_firmware <= 1.30 cpe:2.3:o:mitsubishi:cms-rmd-j_firmware:*:*:*:*:*:*:*:*
mitsubishi pac-yg50eca_firmware <= 2.20 cpe:2.3:o:mitsubishi:pac-yg50eca_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-20595

cvelogic Threat Intelligence