CVE-2021-29086Network attack vector

Unauthenticated sensitive information disclosure via webapi

Published Jun 23, 2021 · Updated Sep 17, 2024

Information disclosure in Synology DiskStation Manager before 6.2.3-25426-3 allows remote attackers to obtain sensitive data. The webapi component returns sensitive information to an unauthorized requester, but Synology has not disclosed the affected endpoint, request, or exposed data. No authentication or user interaction is required, and the reported consequence is limited to confidentiality loss.

CVSS severity5.3
Medium
EPSS probability1.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Synology DiskStation Manager before 6.2.3-25426-3 allows remote attackers to obtain sensitive data. The webapi component returns sensitive information to an unauthorized requester, but Synology has not disclosed the affected endpoint, request, or exposed data. No authentication or user interaction is required, and the reported consequence is limited to confidentiality loss.

The record

CVE
CVE-2021-29086
Published
Jun 23, 2021
Updated
Sep 17, 2024
Vendor
Synology
Product
DiskStation Manager
Classifications
CWE-200, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <6.2.3-25426-3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Synology · DiskStation Managerversion=unspecified <6.2.3-25426-3

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.3Synology Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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