Cyber Resilience

CVE-2021-23836

MediumPublic PoC

Published: 15 January 2021

Published
15 January 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 4.8 CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0040 61.1th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23836 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Flatcore Flatcore. Its CVSS base score is 4.8 (Medium).

Operationally, ranked in the top 38.9% 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

An issue was discovered in flatCore before 2.0.0 build 139. A stored XSS vulnerability was identified in the prefs_smtp_psw HTTP request body parameter for the acp interface. An admin user can inject malicious client-side script into the affected parameter without…

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any form of input sanitization. The injected payload will be executed in the browser of a user whenever one visits the affected module page.

CWE(s)

Related Threats

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

Affected Assets

flatcore
flatcore
≤ 2.0.0

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.

addresses: CWE-79

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

addresses: CWE-79

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

addresses: CWE-79

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

References