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Vulnerability record · CVE-2021-28977 · published 23 June 2021

CVE-2021-28977: Get-simple getsimplecms cross-site scripting vulnerability

Get Simple · Getsimplecms

Cross Site Scripting vulnerability in GetSimpleCMS 3.3.16 in admin/upload.php by adding comments or jpg and other file header information to the content of xla, pages, and gzip files,

4.8 CVSS 3.1 Medium EPSS 0.51% · top 59.2% CWE-79 · Cross-site scripting
4.8CVSS 3.1 base score, v2 3.5
0.51%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Cross Site Scripting vulnerability in GetSimpleCMS 3.3.16 in admin/upload.php by adding comments or jpg and other file header information to the content of xla, pages, and gzip files,

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/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/1336 Third Party Advisory
https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1336 Third Party Advisory

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Related vulnerabilities

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

9.8CVE-2023-6188Get-simple getsimplecms code injection vulnerabilityA vulnerability was found in GetSimpleCMS 3.3.16/3.4.0a. It has been rated as critical. This issue affects some unknown processing of the file /admin…EPSS 0.97%9.8CVE-2023-46042Get-simple getsimplecms code injection vulnerabilityAn issue in GetSimpleCMS v.3.4.0a allows a remote attacker to execute arbitrary code via a crafted payload to the phpinfo().EPSS 23%9.1CVE-2020-18191Get-simple getsimplecms path traversal vulnerabilityGetSimpleCMS-3.3.15 is affected by directory traversal. Remote attackers are able to delete arbitrary files via /GetSimpleCMS-3.3.15/admin/log.phpEPSS 2.1%8.7CVE-2013-10032Get-simple getsimplecms missing authentication for critical function vulnerabilityAn authenticated remote code execution vulnerability exists in GetSimpleCMS version 3.2.1. The application’s upload.php endpoint allows authenticated…EPSS 3.7%8.6CVE-2021-47778Get-simple getsimplecms code injection vulnerabilityGetSimple CMS My SMTP Contact Plugin 1.1.2 contains a PHP code injection vulnerability. An authenticated administrator can inject arbitrary PHP code …EPSS 1.3%8.5CVE-2021-47860Get-simple getsimplecms cross-site request forgery vulnerabilityGetSimple CMS Custom JS 0.1 plugin contains a cross-site request forgery vulnerability that allows unauthenticated attackers to inject arbitrary clie…EPSS 0.27%7.2CVE-2021-28976Get-simple getsimplecms unrestricted file upload vulnerabilityRemote Code Execution vulnerability in GetSimpleCMS before 3.3.16 in admin/upload.php via phar filess.EPSS 7.5%6.9CVE-2024-11125Get-simple getsimplecms cross-site request forgery vulnerabilityA vulnerability was found in GetSimpleCMS 3.3.16 and classified as problematic. This issue affects some unknown processing of the file /admin/profile…EPSS 0.38%

Source: NIST National Vulnerability Database (record CVE-2021-28977), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.