CVE-2021-33184Network attack vector

Authenticated arbitrary file read via task SSRF

Published Jun 1, 2021 · Updated Sep 17, 2024

SSRF in Synology Download Station's task management component before 3.8.15-3563 allows remote authenticated users to read arbitrary files. Synology has not published the request parameter, handler, or server-side fetch operation that permits file-scheme access. A valid Download Station account and network access to its web interface are required, and the documented consequence is file disclosure only.

CVSS severity7.7
High
EPSS probability1.00%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Synology Download Station's task management component before 3.8.15-3563 allows remote authenticated users to read arbitrary files. Synology has not published the request parameter, handler, or server-side fetch operation that permits file-scheme access. A valid Download Station account and network access to its web interface are required, and the documented consequence is file disclosure only.

The record

CVE
CVE-2021-33184
Published
Jun 1, 2021
Updated
Sep 17, 2024
Vendor
Synology
Product
Download Station
Classifications
CWE-918, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 1, 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 <3.8.15-3563

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Synology · Download Stationversion=unspecified <3.8.15-3563

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:N
7.7Synology Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1005Data from Local System

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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