What is CVE-2021-3310?

CVE-2021-3310 is a high-severity vulnerability in Westerndigital My Cloud Dl2100, classified under Improper Link Resolution Before File Access. CVSS score: 7.8/10. Published 2021-03-10.

How severe is CVE-2021-3310?

High severity. CVSS v3 base score is 7.8 out of 10.

Is CVE-2021-3310 known to be exploited?

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

Vulnerability in Westerndigital My Cloud Dl2100

CVE-2021-3310

Western Digital My Cloud OS 5 devices before 5.10.122 mishandle Symbolic Link Following on SMB and AFP shares. This can lead to code execution and information disclosure (by reading local files).

Published 2021-03-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (61.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-59 — Improper Link Resolution Before File Access

Public proof-of-concept exploits

References

www.westerndigital.com/support/productsecurity/wdc-21002-my-cloud-firmware-vers… (Vendor Advisory)
www.zerodayinitiative.com/advisories/ZDI-21-277/ (Third Party Advisory)

Frequently asked questions

What is CVE-2021-3310?: CVE-2021-3310 is a high-severity vulnerability in Westerndigital My Cloud Dl2100, classified under Improper Link Resolution Before File Access. CVSS score: 7.8/10. Published 2021-03-10.
How severe is CVE-2021-3310?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2021-3310 known to be exploited?: 13 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.