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Fencer Intel
medium 5.4

CVE-2021-21312 json

Stored XSS on documents

published 5y ago modified 4mo ago also EUVD-2021-8664

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

GLPI is open source software which stands for Gestionnaire Libre de Parc Informatique and it is a Free Asset and IT Management Software package. In GLPI before verison 9.5.4, there is a vulnerability within the document upload function (Home > Management > Documents > Add, or /front/document.form.php endpoint), indeed one of the form field: "Web Link" is not properly sanitized and a malicious user (who has document upload rights) can use it to deliver JavaScript payload. For example if you use the following payload: " accesskey="x" onclick="alert(1)" x=", the content will be saved within the database without any control. And then once you return to the summary documents page, by clicking on the "Web Link" of the newly created file it will create a new empty tab, but on the initial tab the pop-up "1" will appear.

Patch / fix

  • glpi-project glpi 9.5.4

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-21312 updated cvss 4.8

glpi: Stored XSS on documents

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:N/I:H/A:N
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

  • glpi-project glpi

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.