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Vulnerability record · CVE-2018-19420 · published 21 November 2018

CVE-2018-19420: Get-simple getsimple cms unrestricted file upload vulnerability

Get Simple · Getsimple Cms

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

3.8 CVSS 3.0 Low EPSS 0.78% · top 45.9% CWE-434 · Unrestricted file upload
3.8CVSS 3.0 base score, v2 4.0
0.78%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

In GetSimpleCMS 3.3.15, admin/upload.php blocks .html uploads but there are several alternative cases in which HTML can be executed, such as a file with no extension or an unrecognized extension (e.g., the test or test.asdf filename), because of admin/upload-uploadify.php, and validate_safe_file in admin/inc/security_functions.php.

CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1301 ExploitThird Party Advisory
https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1301 ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2022-41544Get-simple getsimple cms code injection vulnerabilityGetSimple CMS v3.3.16 was discovered to contain a remote code execution (RCE) vulnerability via the edited_file parameter in admin/theme-edit.php.EPSS 11%9.8CVE-2019-11231GetSimple CMS theme-edit.php arbitrary file upload and auth bypassGetSimple CMS through 3.3.15 has insufficient input sanitation in admin/theme-edit.php, allowing an authenticated user to upload files with arbitrary…EPSS 72%analysed8.8CVE-2018-17103Get-simple getsimple cms cross-site request forgery vulnerabilityAn issue was discovered in GetSimple CMS v3.3.13. There is a CSRF vulnerability that can change the administrator's password via admin/settings.php. …EPSS 0.65%7.5CVE-2014-8722Get-simple getsimple cms information exposure vulnerabilityGetSimple CMS 3.3.4 allows remote attackers to obtain sensitive information via a direct request to (1) data/users/<username>.xml, (2) backups/users/…EPSS 14%6.1CVE-2020-23839Get-simple getsimple cms cross-site scripting vulnerabilityA Reflected Cross-Site Scripting (XSS) vulnerability in GetSimple CMS v3.3.16, in the admin/index.php login portal webpage, allows remote attackers t…EPSS 10%6.1CVE-2013-1420Get-simple getsimple cms cross-site scripting vulnerabilityMultiple cross-site scripting (XSS) vulnerabilities in GetSimple CMS before 3.2.1 allow remote attackers to inject arbitrary web script or HTML via t…EPSS 1.1%6.1CVE-2018-16325Get-simple getsimple cms cross-site scripting vulnerabilityThere is XSS in GetSimple CMS 3.4.0.9 via the admin/edit.php title field.EPSS 0.80%6.1CVE-2018-9173Get-simple getsimple cms cross-site scripting vulnerabilityCross-site scripting (XSS) vulnerability in admin/template/js/uploadify/uploadify.swf in GetSimple CMS 3.3.13 allows remote attackers to inject arbit…EPSS 2.4%

Source: NIST National Vulnerability Database (record CVE-2018-19420), CISA KEV, FIRST EPSS (scores of 2026-09-29). This page is refreshed as NVD updates the record.