CVE-2021-1724 [Medium] | XSS in Dynamics 365 Business Central

CVE-2021-1724 is rated Moderate Risk (46.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.18%). Review affected assets and schedule remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.93%	1.18%	+0.25%
2	2025-11-21	1.05%	0.93%	-0.12%
3	2025-11-18	—	1.05%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.93%

1.18%

+0.25%

2025-11-21

1.05%

0.93%

-0.12%

2025-11-18

—

1.05%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.1	3.1	MEDIUM	`CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. 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:N) Service keeps running; no real outage angle.	1.7	4.0	[email protected]
4.8	3.1	MEDIUM	`CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N` Click to expand Attack vector (AV:A) Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet. 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:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	1.7	2.7	[email protected]
2.3	2.0	LOW	`AV:A/AC:M/Au:S/C:N/I:P/A:N` Click to expand Access vector (AV:A) Requires access to an adjacent network segment. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:S) A single authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	4.4	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.1

3.1

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N Click to expand

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
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:N): Service keeps running; no real outage angle.

1.7

4.0

[email protected]

4.8

3.1

MEDIUM

CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand

Attack vector (AV:A): Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

1.7

2.7

[email protected]

2.3

2.0

LOW

AV:A/AC:M/Au:S/C:N/I:P/A:N Click to expand

Access vector (AV:A): Requires access to an adjacent network segment.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S): A single authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

4.4

2.9

[email protected]

Affected software / configurations for CVE-2021-1724

Vendor	Product	Version	Raw CPE
microsoft	dynamics_365_business_central	2019	cpe:2.3:a:microsoft:dynamics_365_business_central:2019:release_wave_2:::on-premise:::*
microsoft	dynamics_365_business_central	2020	cpe:2.3:a:microsoft:dynamics_365_business_central:2020:release_wave_1::::::
microsoft	dynamics_365_business_central	2020	cpe:2.3:a:microsoft:dynamics_365_business_central:2020:release_wave_2::::::
microsoft	dynamics_nav	2015	cpe:2.3:a:microsoft:dynamics_nav:2015:::::::*
microsoft	dynamics_nav	2016	cpe:2.3:a:microsoft:dynamics_nav:2016:::::::*
microsoft	dynamics_nav	2017	cpe:2.3:a:microsoft:dynamics_nav:2017:::::::*
microsoft	dynamics_nav	2018	cpe:2.3:a:microsoft:dynamics_nav:2018:::::::*

References for CVE-2021-1724

URL	Tags
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1724	Patch Vendor Advisory

URL

CVE-2021-1724 | Microsoft Dynamics Business Central Cross-site Scripting Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2021-1724

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1724

Weakness enumeration for CVE-2021-1724

Affected software / configurations for CVE-2021-1724

References for CVE-2021-1724