CVE-2020-8420Network attack vector

Cross-site request forgery via missing compiler token check

Published Jan 28, 2020 · Updated Aug 4, 2024

Cross-site request forgery in Joomla! CMS 3.0.0 through 3.9.14 allows remote attackers to trigger the LESS compiler via crafted requests. The com_templates LESS compiler accepts a state-changing request without validating a CSRF token, so it treats a forged request as authorized. Exploitation requires user interaction, and Joomla has not published the resulting compiler action or its concrete effect.

CVSS severity8.8
High
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Joomla! CMS 3.0.0 through 3.9.14 allows remote attackers to trigger the LESS compiler via crafted requests. The com_templates LESS compiler accepts a state-changing request without validating a CSRF token, so it treats a forged request as authorized. Exploitation requires user interaction, and Joomla has not published the resulting compiler action or its concrete effect.

The record

CVE
CVE-2020-8420
Published
Jan 28, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-352
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 28, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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-352Cross-Site Request Forgery (CSRF)

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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