HOMEVULNERABILITIESCVE-2021-20595
HIGH

CVE-2021-20595

CWE-611Published: July 13, 2021· Updated: Jun 17, 2026

8.2
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-20595 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.2.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

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/JVNVU93086468/index.html
ADVISORYhttps://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-005_en.pdf
ADVISORYhttps://jvn.jp/vu/JVNVU93086468/index.html
ADVISORYhttps://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-005_en.pdf

All References (4)

→
https://jvn.jp/vu/JVNVU93086468/index.htmlThird Party Advisory
→
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-005_en.pdfVendor Advisory
→
https://jvn.jp/vu/JVNVU93086468/index.htmlThird Party Advisory
→
https://www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-005_en.pdfVendor Advisory

Quick Facts

CVE IDCVE-2021-20595
CVSS Score8.2 / 10
SeverityHIGH
WeaknessCWE-611
CISA KEVNo
Affected1 vendor(s)
PublishedJul 13, 2021

Related CVEs (CWE-611)

CVE-2018-1000651
10.0
CVE-2018-1000644
10.0
CVE-2017-8110
10.0
CVE-2017-7664
10.0
CVE-2018-1000124
10.0
CVE-2018-1000652
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-20595 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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