CVE-2021-3310

mediumpriority · track · 41EPSS 0.010 · 63 %ileexploit · PoCEURUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

1.01% (63rd) EPSS

CVSS 4.6 · medium

Is it mine?

11 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-27

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).

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–7.8

v2.04.6mediumAV:L/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 6.4

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9

v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.4highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-59USprimaryCWE-59US

exploits (1)

Public proof-of-concept and weaponised exploit code.

piffd0s/CVE-2021-3310Western Digital MyCloud PR4100 Link Resolution Information Disclosure VulnerabilityPoC · poc_in_github

affected products (11)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
Western Digital Corporation My Cloud DL2100≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud DL4100≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud EX2 Ultra≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud EX2100≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud EX4100≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud Mirror Gen 2≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud OS≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud PR2100≤ 5.10.122fstec_bduRU
Western Digital Corporation My Cloud PR4100≤ 5.10.122fstec_bduRU
westerndigital my cloud os< 5.10.122nvdUScpe:2.3:o:westerndigital:my_cloud_os:*:*:*:*:*:*:*:*

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu nvd NVD CVE.org MITRE

published 2021-03-10modified 2026-06-17

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references (7)

External citations — patches, advisories, analysis.

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