CVE-2019-9951 [Critical] | File Upload / RCE in My Cloud Mirror Gen 2 Firmware

Western Digital My Cloud, My Cloud Mirror Gen2, My Cloud EX2 Ultra, My Cloud EX2100, My Cloud EX4100, My Cloud DL2100, My Cloud DL4100, My Cloud PR2100 and My Cloud PR4100 firmware before 2.31.174 is affected by an unauthenticated file upload vulnerability. The page web/jquery/uploader/uploadify.php can be accessed without any credentials, and allows uploading arbitrary files to any location on the attached storage.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-03-25	1.33%	0.96%	-0.37%
2	2025-03-30	2.55%	1.33%	-1.22%
3	2025-03-29	—	2.55%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-03-25

1.33%

0.96%

-0.37%

2025-03-30

2.55%

1.33%

-1.22%

2025-03-29

—

2.55%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.0	CRITICAL	`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/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:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.0

CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/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:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

Affected software / configurations for CVE-2019-9951

Vendor	Product	Version	Raw CPE
western_digital	my_cloud_mirror_gen_2_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_mirror_gen_2_firmware::::::::
western_digital	my_cloud_ex2_ultra_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_ex2_ultra_firmware::::::::
western_digital	my_cloud_ex2100_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_ex2100_firmware::::::::
western_digital	my_cloud_ex4100	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_ex4100::::::::
western_digital	my_cloud_dl2100	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_dl2100::::::::
western_digital	my_cloud_dl4100_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_dl4100_firmware::::::::
western_digital	my_cloud_pr2100_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_pr2100_firmware::::::::
western_digital	my_cloud_pr4100	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_pr4100::::::::
western_digital	my_cloud_firmware	< 2.31.174	cpe:2.3:o:western_digital:my_cloud_firmware::::::::

References for CVE-2019-9951

URL	Tags
https://bnbdr.github.io/posts/wd/
https://community.wd.com/t/new-release-my-cloud-firmware-versions-2-31-174-3-26-19/235932	Release Notes Third Party Advisory
https://github.com/bnbdr/wd-rce/
https://support.wdc.com/downloads.aspx?g=2702&lang=en	Third Party Advisory

URL

CVE-2019-9951

Exploit prediction scoring system (EPSS) score for CVE-2019-9951

Common vulnerability scoring system (CVSS) metrics for CVE-2019-9951

Weakness enumeration for CVE-2019-9951

Affected software / configurations for CVE-2019-9951

References for CVE-2019-9951