HOMEVULNERABILITIESCVE-2021-20593
HIGH

CVE-2021-20593

CWE-287Published: July 13, 2021· Updated: Jun 17, 2026

7.1
CVSS v3.1

Official Description

Incorrect Implementation of Authentication Algorithm in Mitsubishi Electric Air Conditioning System/Centralized Controllers (G-50A Ver.2.50 to Ver. 3.35, GB-50A Ver.2.50 to Ver. 3.35, 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) and Air Conditioning System/Expansion Controllers (PAC-YG50ECA Ver.2.20 and prior) allows a remote authenticated attacker to impersonate administrators to disclose configuration information of the air conditioning system and tamper information (e.g. operation information and configuration of air conditioning system) by exploiting this vulnerability.

NVD Source

Technical Analysis

CVE-2021-20593 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 7.1.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityHigh
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

Affected Vendors & Products

mitsubishi38 product(s)
g-50a firmwareg-50agb-50a firmwaregb-50aag-150a-a firmwareag-150a-aag-150a-j firmwareag-150a-jgb-50ada-a firmwaregb-50ada-agb-50ada-j firmwaregb-50ada-j+26
Source: NVD CPE · 38 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://jvn.jp/vu/JVNVU96046575/index.html
ADVISORYhttps://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-004_en.pdf
ADVISORYhttps://jvn.jp/vu/JVNVU96046575/index.html
ADVISORYhttps://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-004_en.pdf

All References (4)

→
https://jvn.jp/vu/JVNVU96046575/index.htmlThird Party Advisory
→
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-004_en.pdfVendor Advisory
→
https://jvn.jp/vu/JVNVU96046575/index.htmlThird Party Advisory
→
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-004_en.pdfVendor Advisory

Quick Facts

CVE IDCVE-2021-20593
CVSS Score7.1 / 10
SeverityHIGH
WeaknessCWE-287
CISA KEVNo
Affected1 vendor(s)
PublishedJul 13, 2021

Related CVEs (CWE-287)

CVE-2025-5597
10.0
CVE-2002-2417
10.0
CVE-2026-57216
10.0
CVE-2025-55241
10.0
CVE-2026-42822
10.0
CVE-2007-4747
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-20593 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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