CVE-2021-21365
Published: 27 April 2021
Summary
CVE-2021-21365 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Typo3 Typo3. Its CVSS base score is 5.4 (Medium).
Operationally, ranked in the top 42.8% 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
- 🇪🇺 ENISA EUVD: EUVD-2021-0849
Vulnerability details
Bootstrap Package is a theme for TYPO3. It has been discovered that rendering content in the website frontend is vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. Users of the extension, who have…
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overwritten the affected templates with custom code must manually apply the security fix. Update to version 7.1.2, 8.0.8, 9.1.4, 10.0.10 or 11.0.3 of the Bootstrap Package that fix the problem described. Updated version are available from the TYPO3 extension manager, Packagist and at https://extensions.typo3.org/extension/download/bootstrap_package/.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
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.
Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.
Validates web inputs to reject script-related content that could produce XSS.
Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.