Cyber Resilience

CVE-2024-21908

MediumPublic PoC

Published: 03 January 2024

Published
03 January 2024
Modified
28 November 2025
KEV Added
—
Patch
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CVSS Score v3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.0052 67.1th percentile
Risk Priority 13 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2024-21908 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Tiny Tinymce. Its CVSS base score is 6.1 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 32.9% 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

TinyMCE versions before 5.9.0 are affected by a stored cross-site scripting vulnerability. An unauthenticated and remote attacker could insert crafted HTML into the editor resulting in arbitrary JavaScript execution in another user's browser.

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
Why these techniques?

The stored XSS vulnerability enables unauthenticated remote attackers to inject crafted HTML into TinyMCE, bypassing schema validation and leading to arbitrary JavaScript execution in victims' browsers, facilitating public-facing app exploitation, client-side exploitation for execution, JavaScript interpreter abuse, and content injection.

Affected Assets

tiny
tinymce
≤ 5.9.0

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.

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