CVE intelligence and bounded remediation

CVE-2021-21312 — Glpi-Project Glpi security vulnerability

Medium CVSS 5.4

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.

Severity
Medium
CVSS
5.4 (3.1)
Published
2021-03-03
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

  • glpi-project / glpi

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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