CVE-2021-20809
Published: 26 August 2021
Summary
CVE-2021-20809 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Sixapart Movable Type. Its CVSS base score is 6.1 (Medium).
Operationally, ranked in the top 42.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-8221
Vulnerability details
Cross-site scripting vulnerability in Create screens of Entry, Page, and Content Type of Movable Type (Movable Type 7 r.4903 and earlier (Movable Type 7 Series), Movable Type 6.8.0 and earlier (Movable Type 6 Series), Movable Type Advanced 7 r.4903 and…
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earlier (Movable Type Advanced 7 Series), Movable Type Premium 1.44 and earlier, and Movable Type Premium Advanced 1.44 and earlier) allows remote attackers to inject arbitrary script or HTML via unspecified vectors.
- 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.