CVE-2021-21327Public exploitNetwork attack vector

Unauthenticated object instantiation via unchecked class selection

Published Mar 8, 2021 · Updated Aug 3, 2024

Unsafe reflection in GLPI before 9.5.4 allows remote attackers to instantiate arbitrary available PHP classes via crafted POST data. The ajax/dropdownConnect.php endpoint passes the fromtype parameter to getItemForItemtype(), which calls class_exists() and constructs the selected class without restricting it to valid GLPI item types. No account is required; invoked constructors or destructors can alter or interrupt the core or installed plugins, depending on the classes present.

CVSS severity6.8
Medium
EPSS probability2.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unsafe reflection in GLPI before 9.5.4 allows remote attackers to instantiate arbitrary available PHP classes via crafted POST data. The ajax/dropdownConnect.php endpoint passes the fromtype parameter to getItemForItemtype(), which calls class_exists() and constructs the selected class without restricting it to valid GLPI item types. No account is required; invoked constructors or destructors can alter or interrupt the core or installed plugins, depending on the classes present.

The record

CVE
CVE-2021-21327
Published
Mar 8, 2021
Updated
Aug 3, 2024
Vendor
GLPI Project
Product
GLPI
Classifications
CWE-862, CWE-470, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 8, 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=< 9.5.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GLPI Project · GLPIversion=< 9.5.4

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
6.8GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:H/A:N
5.0NIST NVDAV:N/AC:L/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 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 exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-470Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
T1190Exploit Public-Facing Application

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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