CVE-2021-31439

mediumpriority · track · 36EPSS 0.023 · 83 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

2.33% (83rd) EPSS

CVSS 5.8 · medium

Is it mine?

5 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Synology DiskStation Manager. Authentication is not required to exploit this vulnerablity. The specific flaw exists within the processing of DSI structures in Netatalk. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-12326.

cvss

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

8.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.8–8.8

v2.05.8mediumAV:A/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 6.5 · impact 6.4

v3.18.8highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 2.8 · impact 5.9

v3.08.8highCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.08.8highCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · zdi-disclosures@trendmicro.comexploitability 2.8 · impact 5.9

v3.18.1highCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-787USprimaryCWE-122US

affected products (5)

Products and version ranges known to be affected.

Synology DiskStation Manager≤ 6.1.1-15101-4enisa_euvdEU
debian debian linux= 10.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
debian debian linux= 11.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
netatalk netatalk< 3.1.13nvdUScpe:2.3:a:netatalk:netatalk:*:*:*:*:*:*:*:*
synology diskstation manager6.2 → 6.2.3-25426-3nvdUScpe:2.3:o:synology:diskstation_manager:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-05-21modified 2026-06-17

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+16125 more

references (20)

External citations — patches, advisories, analysis.

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