What is CVE-2018-9148?

CVE-2018-9148 is a critical-severity vulnerability in Westerndigital My Cloud, classified under Improper Authentication. CVSS score: 9.8/10. Published 2018-03-30.

How severe is CVE-2018-9148?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Westerndigital My Cloud

CVE-2018-9148

Western Digital WD My Cloud v04.05.00-320 devices embed the session token (aka PHPSESSID) in filenames, which makes it easier for attackers to bypass authentication by listing a directory. NOTE: this can be exploited in conjunction with CVE-2018-7171 for remote authentication bypass within a product that uses My Cloud.

Vulnerability class: Broken Authentication

Published 2018-03-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.036 (89.1th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.037 · newest: 0.036 · change: -0.001

Affected products

Westerndigital My Cloud
Westerndigital My Cloud Firmware — versions 04.05.00-320

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

exploit-db.com/exploits/44350/ (Exploit, VDB Entry, Third Party Advisory, exploit)

Frequently asked questions

What is CVE-2018-9148?: CVE-2018-9148 is a critical-severity vulnerability in Westerndigital My Cloud, classified under Improper Authentication. CVSS score: 9.8/10. Published 2018-03-30.
How severe is CVE-2018-9148?: Critical severity. CVSS v3 base score is 9.8 out of 10.