Cyber Resilience

CVE-2020-21353

MediumPublic PoC

Published: 06 August 2021

Published
06 August 2021
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0028 51.8th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2020-21353 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Get-Simple Getsimplecms. Its CVSS base score is 5.4 (Medium).

Operationally, ranked in the top 48.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)
CWE-79

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

get-simple
getsimplecms
3.4.0a

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation
addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering
addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

References