What is CVE-2019-9949?

CVE-2019-9949 is a high-severity vulnerability in Westerndigital My Cloud, classified under Improper Link Resolution Before File Access. CVSS score: 8.8/10. Published 2019-05-23.

How severe is CVE-2019-9949?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2019-9949 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Westerndigital My Cloud

CVE-2019-9949

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.

Published 2019-05-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.030 (86.8th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 86.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.031 · newest: 0.030 · change: -0.001

Affected products

Weakness classification (CWE)

CWE-59 — Improper Link Resolution Before File Access

Public proof-of-concept exploits

bnbdr/wd-rce

References

community.wd.com/t/new-release-my-cloud-firmware-versions-2-31-183-05-20-2019/2… (Vendor Advisory)
bnbdr.github.io/posts/wd/ (Exploit, Third Party Advisory)
github.com/bnbdr/wd-rce/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-9949?: CVE-2019-9949 is a high-severity vulnerability in Westerndigital My Cloud, classified under Improper Link Resolution Before File Access. CVSS score: 8.8/10. Published 2019-05-23.
How severe is CVE-2019-9949?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2019-9949 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.