CVE-2020-9044 [High] | Denial of Service in Metasys Application And D…

XXE vulnerability exists in the Metasys family of product Web Services which has the potential to facilitate DoS attacks or harvesting of ASCII server files. This affects Johnson Controls' Metasys Application and Data Server (ADS, ADS-Lite) versions 10.1 and prior; Metasys Extended Application and Data Server (ADX) versions 10.1 and prior; Metasys Open Data Server (ODS) versions 10.1 and prior; Metasys Open Application Server (OAS) version 10.1; Metasys Network Automation Engine (NAE55 only) versions 9.0.1, 9.0.2, 9.0.3, 9.0.5, 9.0.6; Metasys Network Integration Engine (NIE55/NIE59) versions 9.0.1, 9.0.2, 9.0.3, 9.0.5, 9.0.6; Metasys NAE85 and NIE85 versions 10.1 and prior; Metasys LonWorks Control Server (LCS) versions 10.1 and prior; Metasys System Configuration Tool (SCT) versions 13.2 and prior; Metasys Smoke Control Network Automation Engine (NAE55, UL 864 UUKL/ORD-C100-13 UUKLC 10th Edition Listed) version 8.1.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.27%	1.29%	+1.02%
2	2025-11-21	0.40%	0.27%	-0.13%
3	2025-11-18	—	0.40%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.27%

1.29%

+1.02%

2025-11-21

0.40%

0.27%

-0.13%

2025-11-18

—

0.40%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.5	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:N) Doesn’t really leak secrets in a meaningful way. 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	3.6	[email protected]
9.1	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:H) Serious risk that confidential data gets exposed in a big way. 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	5.2	[email protected]
6.4	2.0	MEDIUM	`AV:N/AC:L/Au:N/C:P/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:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:P) Partial availability impact.	10.0	4.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.5

3.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:N): Doesn’t really leak secrets in a meaningful way.
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

3.6

[email protected]

9.1

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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:H): Serious risk that confidential data gets exposed in a big way.
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

5.2

[email protected]

6.4

2.0

MEDIUM

AV:N/AC:L/Au:N/C:P/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:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

4.9

[email protected]

Affected software / configurations for CVE-2020-9044

Vendor	Product	Version	Raw CPE
johnsoncontrols	metasys_application_and_data_server	<= 10.1	cpe:2.3:a:johnsoncontrols:metasys_application_and_data_server::::::::
johnsoncontrols	metasys_application_and_data_server	<= 10.1	cpe:2.3:a:johnsoncontrols:metasys_application_and_data_server:::::lite:::*
johnsoncontrols	metasys_extended_application_and_data_server	<= 10.1	cpe:2.3:a:johnsoncontrols:metasys_extended_application_and_data_server::::::::
johnsoncontrols	metasys_lonworks_control_server	<= 10.1	cpe:2.3:a:johnsoncontrols:metasys_lonworks_control_server::::::::
johnsoncontrols	metasys_open_application_server	10.1	cpe:2.3:a:johnsoncontrols:metasys_open_application_server:10.1:::::::*
johnsoncontrols	metasys_open_data_server	<= 10.1	cpe:2.3:a:johnsoncontrols:metasys_open_data_server::::::::
johnsoncontrols	metasys_system_configuration_tool	<= 13.2	cpe:2.3:a:johnsoncontrols:metasys_system_configuration_tool::::::::
johnsoncontrols	nae55_firmware	9.0.1	cpe:2.3:o:johnsoncontrols:nae55_firmware:9.0.1:::::::*
johnsoncontrols	nae55_firmware	9.0.2	cpe:2.3:o:johnsoncontrols:nae55_firmware:9.0.2:::::::*
johnsoncontrols	nae55_firmware	9.0.3	cpe:2.3:o:johnsoncontrols:nae55_firmware:9.0.3:::::::*
johnsoncontrols	nae55_firmware	9.0.5	cpe:2.3:o:johnsoncontrols:nae55_firmware:9.0.5:::::::*
johnsoncontrols	nae55_firmware	9.0.6	cpe:2.3:o:johnsoncontrols:nae55_firmware:9.0.6:::::::*
johnsoncontrols	nie55_firmware	9.0.1	cpe:2.3:o:johnsoncontrols:nie55_firmware:9.0.1:::::::*
johnsoncontrols	nie55_firmware	9.0.2	cpe:2.3:o:johnsoncontrols:nie55_firmware:9.0.2:::::::*
johnsoncontrols	nie55_firmware	9.0.3	cpe:2.3:o:johnsoncontrols:nie55_firmware:9.0.3:::::::*
johnsoncontrols	nie55_firmware	9.0.5	cpe:2.3:o:johnsoncontrols:nie55_firmware:9.0.5:::::::*
johnsoncontrols	nie55_firmware	9.0.6	cpe:2.3:o:johnsoncontrols:nie55_firmware:9.0.6:::::::*
johnsoncontrols	nie59_firmware	9.0.1	cpe:2.3:o:johnsoncontrols:nie59_firmware:9.0.1:::::::*
johnsoncontrols	nie59_firmware	9.0.2	cpe:2.3:o:johnsoncontrols:nie59_firmware:9.0.2:::::::*
johnsoncontrols	nie59_firmware	9.0.3	cpe:2.3:o:johnsoncontrols:nie59_firmware:9.0.3:::::::*
johnsoncontrols	nie59_firmware	9.0.5	cpe:2.3:o:johnsoncontrols:nie59_firmware:9.0.5:::::::*
johnsoncontrols	nie59_firmware	9.0.6	cpe:2.3:o:johnsoncontrols:nie59_firmware:9.0.6:::::::*
johnsoncontrols	nae85_firmware	<= 10.1	cpe:2.3:o:johnsoncontrols:nae85_firmware::::::::
johnsoncontrols	nie85_firmware	<= 10.1	cpe:2.3:o:johnsoncontrols:nie85_firmware::::::::
johnsoncontrols	nae55_firmware	8.1	cpe:2.3:o:johnsoncontrols:nae55_firmware:8.1:::::::*
johnsoncontrols	ul_864_uukl_firmware	8.1	cpe:2.3:o:johnsoncontrols:ul_864_uukl_firmware:8.1:::::::*
johnsoncontrols	ord-c100-13_uuklc_firmware	8.1	cpe:2.3:o:johnsoncontrols:ord-c100-13_uuklc_firmware:8.1:::::::*

References for CVE-2020-9044

URL	Tags
https://www.johnsoncontrols.com/cyber-solutions/security-advisories	Vendor Advisory
https://www.us-cert.gov/ics/advisories/icsa-20-070-05	Third Party Advisory US Government Resource

URL

CVE-2020-9044 | Metasys Improper Restriction of XML External Entity Reference

Exploit prediction scoring system (EPSS) score for CVE-2020-9044

Common vulnerability scoring system (CVSS) metrics for CVE-2020-9044

Weakness enumeration for CVE-2020-9044

Affected software / configurations for CVE-2020-9044

References for CVE-2020-9044