CVE-2019-9949: Westerndigital My Cloud DL2100 Firmware

High severity, CVSS 8.8. EPSS: 3% chance of exploitation in the next 30 days.

Western Digital My Cloud Cloud, Mirror Gen2, EX2 Ultra, EX2100, EX4100, DL2100, DL4100, PR2100 and PR4100 before firmware 2.31.183 are affected by a code execution (as root, starting from a low-privilege user session) vulnerability. The cgi-bin/webfile_mgr.cgi file allows arbitrary file write by abusing symlinks. Specifically, this occurs by uploading a tar archive that contains a symbolic link, then uploading another archive that writes a file to the link using the "cgi_untar" command. Other commands might also be susceptible. Code can be executed because the "name" parameter passed to the cgi_unzip command is not sanitized.

Affected products

• Westerndigital My Cloud DL2100 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud DL4100 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud EX2100 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud EX2 Ultra Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud EX4100 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud Mirror GEN2 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud PR2100 Firmware: before 2.31.183 (fixed in 2.31.183)
• Westerndigital My Cloud PR4100 Firmware: before 2.31.183 (fixed in 2.31.183)

Published 2019-05-23. Last modified 2026-06-17.