CVE-2021-29116Network attack vector

Browser code execution via stored query strings

Published Dec 7, 2021 · Updated Apr 10, 2025

Stored XSS in feature services in Esri ArcGIS Server 10.8.1 and 10.9 allows remote attackers to execute JavaScript via crafted queries. Feature services accept attacker-controlled query strings, persist them without adequate output neutralization, and later render them in a user's browser. Unauthenticated access requires an anonymously available service, and execution requires a user to access the stored content; services are not anonymous by default.

CVSS severity6.1
Medium
EPSS probability0.78%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in feature services in Esri ArcGIS Server 10.8.1 and 10.9 allows remote attackers to execute JavaScript via crafted queries. Feature services accept attacker-controlled query strings, persist them without adequate output neutralization, and later render them in a user's browser. Unauthenticated access requires an anonymously available service, and execution requires a user to access the stored content; services are not anonymous by default.

The record

CVE
CVE-2021-29116
Published
Dec 7, 2021
Updated
Apr 10, 2025
Vendor
Esri
Product
ArcGIS Server
Classifications
CWE-79, 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=10.8.1 <10.9.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Esri · ArcGIS Serverversion=10.8.1 <10.9.0

Published CVSS scores

6.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1Environmental Systems Research Institute, Inc.CVSS:3.1/AV:N/AC:L/PR:N/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
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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