CVE-2021-34356Network attack vector

Browser-context compromise via stored script injection

Published Oct 1, 2021 · Updated Sep 16, 2024

Stored cross-site scripting in QNAP Photo Station before 6.0.18 allows remote authenticated users to inject malicious code. QNAP has not disclosed the affected input, storage location, or output-rendering operation that fails to neutralize the stored content. Exploitation requires low privileges and user interaction, enabling access to browser-visible data and rendered-content changes without service interruption.

CVSS severity7.6
High
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in QNAP Photo Station before 6.0.18 allows remote authenticated users to inject malicious code. QNAP has not disclosed the affected input, storage location, or output-rendering operation that fails to neutralize the stored content. Exploitation requires low privileges and user interaction, enabling access to browser-visible data and rendered-content changes without service interruption.

The record

CVE
CVE-2021-34356
Published
Oct 1, 2021
Updated
Sep 16, 2024
Vendor
Linn Products Limited
Product
Photo Station
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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 <6.0.18 ( 2021/09/01 )

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Linn Products Limited · Photo Stationversion=unspecified <6.0.18 ( 2021/09/01 )

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
7.6QNAP Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

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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