CVE-2021-21801Public exploitNetwork attack vector

JavaScript execution via unsanitized graph parameter

Published Jul 16, 2021 · Updated Aug 3, 2024

Reflected XSS in Advantech R-SeeNet 2.4.12 allows remote attackers to execute JavaScript via a crafted graph parameter URL. The device_graph_page.php script copies the unsanitized graph query value directly into an img element's src attribute, permitting attribute breakout. A victim must visit the crafted URL; no login is required, and the script runs in the victim's browser under the R-SeeNet origin.

CVSS severity9.6
Critical
EPSS probability63.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Advantech R-SeeNet 2.4.12 allows remote attackers to execute JavaScript via a crafted graph parameter URL. The device_graph_page.php script copies the unsanitized graph query value directly into an img element's src attribute, permitting attribute breakout. A victim must visit the crafted URL; no login is required, and the script runs in the victim's browser under the R-SeeNet origin.

The record

CVE
CVE-2021-21801
Published
Jul 16, 2021
Updated
Aug 3, 2024
Vendor
Advantech
Product
R-SeeNet
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 16, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=Advantech R-SeeNet 2.4.12 (20.10.2020)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Advantech · R-SeeNetversion=Advantech R-SeeNet 2.4.12 (20.10.2020)

Published CVSS scores

9.6Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:R/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

Public exploit references

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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