CVE-2021-29113Network attack vector

Unauthenticated HTML injection via help documentation

Published Dec 7, 2021 · Updated Apr 10, 2025

A remote file inclusion flaw in Esri ArcGIS Server 10.9.0 and earlier allows remote attackers to inject attacker-supplied HTML via help pages. The help-documentation handler includes attacker-controlled remote content in the rendered response instead of constraining the included resource, allowing markup to reach a viewer. The attack requires no ArcGIS authentication but does require a user to request or follow the crafted help-page link; impact is limited to integrity-affecting page content injection, with no documented server takeover or service interruption.

CVSS severity4.7
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A remote file inclusion flaw in Esri ArcGIS Server 10.9.0 and earlier allows remote attackers to inject attacker-supplied HTML via help pages. The help-documentation handler includes attacker-controlled remote content in the rendered response instead of constraining the included resource, allowing markup to reach a viewer. The attack requires no ArcGIS authentication but does require a user to request or follow the crafted help-page link; impact is limited to integrity-affecting page content injection, with no documented server takeover or service interruption.

The record

CVE
CVE-2021-29113
Published
Dec 7, 2021
Updated
Apr 10, 2025
Vendor
Esri
Product
ArcGIS Server
Classifications
CWE-98, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 7, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 10, 2025Record 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=10.9 <=10.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Esri · ArcGIS Serverversion=10.9 <=10.9.0

Published CVSS scores

4.7Esri CNACVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:N/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 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-98Improper Control of Filename for Include/Require Statement
T1189Drive-by Compromise

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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