Remote code execution in Western Digital My Cloud OS 5
| Risk | High |
| Patch available | YES |
| Number of vulnerabilities | 1 |
| CVE-ID | CVE-2021-44142 |
| CWE-ID | CWE-787 |
| Exploitation vector | Network |
| Public exploit | Public exploit code for vulnerability #1 is available. |
| Vulnerable software |
WD Cloud Hardware solutions / Other hardware appliances My Cloud EX2100 Hardware solutions / Other hardware appliances My Cloud DL4100 Hardware solutions / Other hardware appliances My Cloud DL2100 Hardware solutions / Other hardware appliances My Cloud Mirror Gen 2 Hardware solutions / Other hardware appliances My Cloud EX4100 Hardware solutions / Other hardware appliances My Cloud EX2 Ultra Hardware solutions / Other hardware appliances My Cloud PR4100 Hardware solutions / Other hardware appliances My Cloud PR2100 Hardware solutions / Other hardware appliances My Cloud Hardware solutions / Office equipment, IP-phones, print servers My Cloud OS 5 Operating systems & Components / Operating system |
| Vendor | Western Digital |
Security Bulletin
This security bulletin contains one high risk vulnerability.
1) Out-of-bounds write
EUVDB-ID: #VU60186
Risk: High
CVSSv4.0: 8.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/U:Amber]
CVE-ID: CVE-2021-44142
CWE-ID:
CWE-787 - Out-of-bounds write
Exploit availability: Yes
DescriptionThe vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error when processing EA metadata while opening files in smbd within the VFS Samba module (vfs_fruit). A remote attacker with ability to write to file's extended attributes can trigger an out-of-bounds write and execute arbitrary code with root privileges.
Note, the vulnerability in vfs_fruit exists in the default configuration of the fruit VFS module using fruit:metadata=netatalk or fruit:resource=file.
Install update from vendor's website.
Vulnerable software versionsWD Cloud: All versions
My Cloud: All versions
My Cloud EX2100: All versions
My Cloud DL4100: All versions
My Cloud DL2100: All versions
My Cloud Mirror Gen 2: All versions
My Cloud EX4100: All versions
My Cloud EX2 Ultra: All versions
My Cloud PR4100: All versions
My Cloud PR2100: All versions
My Cloud OS 5: before 5.21.104
CPE2.3- cpe:2.3:h:western_digital:wd_cloud:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_ex2100:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_dl4100:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_dl2100:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_mirror_gen_2:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_ex4100:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_ex2_ultra:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_pr4100:*:*:*:*:*:*:*:*
- cpe:2.3:h:western_digital:my_cloud_pr2100:*:*:*:*:*:*:*:*
- cpe:2.3:o:western_digital:my_cloud_os_5:*:*:*:*:*:*:*:*
https://www.westerndigital.com/support/product-security/wdc-22006-my-cloud-os5-firmware-5-21-104
Q & A
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.
