CVE-2021-33181Network attack vector

Authenticated intranet access via arbitrary webapi requests

Published Jun 1, 2021 · Updated Sep 17, 2024

SSRF in the webapi component of Synology Video Station before 2.4.10-1632 allows remote authenticated users to access intranet resources. The webapi component forwards an attacker-chosen request to an intranet destination, but Synology has not disclosed the endpoint or missing validation. A high-privilege Video Station account is required, and successful exploitation can direct requests into otherwise unreachable intranet services.

CVSS severity6.6
Medium
EPSS probability0.97%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in the webapi component of Synology Video Station before 2.4.10-1632 allows remote authenticated users to access intranet resources. The webapi component forwards an attacker-chosen request to an intranet destination, but Synology has not disclosed the endpoint or missing validation. A high-privilege Video Station account is required, and successful exploitation can direct requests into otherwise unreachable intranet services.

The record

CVE
CVE-2021-33181
Published
Jun 1, 2021
Updated
Sep 17, 2024
Vendor
Synology
Product
Synology Video Station
Classifications
CWE-918
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 <2.4.10-1632

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Synology · Synology Video Stationversion=unspecified <2.4.10-1632

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
6.6Synology Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:L
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

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)

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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