CVE-2021-1645 [Medium] | Information Disclosure in Windows 10

CVE-2021-1645 is rated Moderate Risk (57.1/100): CVSS Medium severity, with high exploitation likelihood (EPSS 37.21%, 97th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +3.05% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-14	34.16%	37.21%	+3.05%
2	2026-03-11	28.18%	34.16%	+5.98%
3	2025-12-03	—	28.18%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-14

34.16%

37.21%

+3.05%

2026-03-11

28.18%

34.16%

+5.98%

2025-12-03

—

28.18%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.0	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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: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:N) Service keeps running; no real outage angle.	1.3	3.6	[email protected]
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. 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:N) Service keeps running; no real outage angle.	1.8	3.6	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:N/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:N) No integrity impact. Availability impact (A:N) No availability impact.	8.6	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.0

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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: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:N): Service keeps running; no real outage angle.

1.3

3.6

[email protected]

5.5

3.1

MEDIUM

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
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:N): Service keeps running; no real outage angle.

1.8

3.6

[email protected]

4.3

2.0

MEDIUM

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

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:N): No integrity impact.
Availability impact (A:N): No availability impact.

8.6

2.9

[email protected]

Affected software / configurations for CVE-2021-1645

Vendor	Product	Version	Raw CPE
microsoft	windows_10	20h2	cpe:2.3:o:microsoft:windows_10:20h2:::::::*
microsoft	windows_10	1607	cpe:2.3:o:microsoft:windows_10:1607:::::::*
microsoft	windows_10	1809	cpe:2.3:o:microsoft:windows_10:1809:::::::*
microsoft	windows_10	1909	cpe:2.3:o:microsoft:windows_10:1909:::::::*
microsoft	windows_10	2004	cpe:2.3:o:microsoft:windows_10:2004:::::::*
microsoft	windows_server_2016	—	cpe:2.3:o:microsoft:windows_server_2016:-:::::::*
microsoft	windows_server_2016	20h2	cpe:2.3:o:microsoft:windows_server_2016:20h2:::::::*
microsoft	windows_server_2016	1909	cpe:2.3:o:microsoft:windows_server_2016:1909:::::::*
microsoft	windows_server_2016	2004	cpe:2.3:o:microsoft:windows_server_2016:2004:::::::*
microsoft	windows_server_2019	—	cpe:2.3:o:microsoft:windows_server_2019:-:::::::*

References for CVE-2021-1645

URL	Tags
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1645
http://packetstormsecurity.com/files/161816/Microsoft-Windows-Containers-DP-API-Cryptography-Flaw.html
http://seclists.org/fulldisclosure/2021/Mar/33
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1645

URL

CVE-2021-1645 | Windows Docker Information Disclosure Vulnerability

Exploit prediction scoring system (EPSS) score for CVE-2021-1645

Common vulnerability scoring system (CVSS) metrics for CVE-2021-1645

Weakness enumeration for CVE-2021-1645

Affected software / configurations for CVE-2021-1645

References for CVE-2021-1645