How severe is CVE-2020-21353?

CVE-2020-21353 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-21353 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21353?

CVE-2020-21353 affects Get-simple Getsimplecms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-21353?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-21353 published?

CVE-2020-21353 was published on 2021-08-06 and last updated on 2026-06-17.

CVE-2020-21353

CVE-2020-21353 is a medium-severity vulnerability in Get-simple Getsimplecms with a CVSS 3.x base score of 5.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v2: 3.5
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Get-simple Getsimplecms
Published: 2021-08-06
Last modified: 2026-06-17

Description

A stored cross site scripting (XSS) vulnerability in /admin/snippets.php of GetSimple CMS 3.4.0a allows attackers to execute arbitrary web scripts or HTML via crafted payload in the Edit Snippets module.

Frequently asked questions

What is CVE-2020-21353?: A stored cross site scripting (XSS) vulnerability in /admin/snippets.php of GetSimple CMS 3.4.0a allows attackers to execute arbitrary web scripts or HTML via crafted payload in the Edit Snippets module.
How severe is CVE-2020-21353?: CVE-2020-21353 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-21353 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21353?: CVE-2020-21353 affects Get-simple Getsimplecms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-21353?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-21353 published?: CVE-2020-21353 was published on 2021-08-06 and last updated on 2026-06-17.

References

https://github.com/GetSimpleCMS/GetSimpleCMS/issues/1319

Affected products (1)

cpe:2.3:a:get-simple:getsimplecms:3.4.0a:*:*:*:*:*:*:*

More vulnerabilities in Get-simple Getsimplecms

CVE-2023-46042 — Critical (CVSS 9.8): An issue in GetSimpleCMS v.3.4.0a allows a remote attacker to execute arbitrary code via a crafted payload to the…
CVE-2020-18191 — Critical (CVSS 9.1): GetSimpleCMS-3.3.15 is affected by directory traversal. Remote attackers are able to delete arbitrary files via…
CVE-2013-10032 — High (CVSS 8.8): An authenticated remote code execution vulnerability exists in GetSimpleCMS version 3.2.1. The application’s…
CVE-2021-47778 — High (CVSS 7.2): GetSimple CMS My SMTP Contact Plugin 1.1.2 contains a PHP code injection vulnerability. An authenticated administrator…
CVE-2021-28976 — High (CVSS 7.2): Remote Code Execution vulnerability in GetSimpleCMS before 3.3.16 in admin/upload.php via phar filess.
CVE-2021-47830 — Medium (CVSS 6.5): GetSimple CMS My SMTP Contact Plugin 1.1.1 contains a cross-site request forgery (CSRF) vulnerability. Attackers can…

All CVEs affecting Get-simple Getsimplecms →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →