CVE-2021-3486Public exploitNetwork attack vector

Stored XSS via unsanitized plugin metadata

Published May 26, 2021 · Updated Aug 3, 2024

Stored XSS in plugin metadata in GLPI 9.5.4 allows remote attackers to execute JavaScript in an administrator's browser. During plugin installation, GLPI loads setup.php and renders fields such as author, version, and license without sanitizing their content. Exploitation requires placing a crafted plugin in the plugins directory and a victim loading its installation information, exposing data and actions available to that browser session.

CVSS severity6.1
Medium
EPSS probability1.39%
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 plugin metadata in GLPI 9.5.4 allows remote attackers to execute JavaScript in an administrator's browser. During plugin installation, GLPI loads setup.php and renders fields such as author, version, and license without sanitizing their content. Exploitation requires placing a crafted plugin in the plugins directory and a victim loading its installation information, exposing data and actions available to that browser session.

The record

CVE
CVE-2021-3486
Published
May 26, 2021
Updated
Aug 3, 2024
Vendor
GLPI Project
Product
GLPI
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 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=glpi 9.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GLPI Project · GLPIversion=glpi 9.5.4

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
4.3NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:N/I:P/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

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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