CVE-2021-43721
Published: 28 March 2022
Summary
CVE-2021-43721 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Leanote Leanote. Its CVSS base score is 6.1 (Medium).
Operationally, ranked in the top 37.1% 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-2021-30628
Vulnerability details
Leanote 2.7.0 is vulnerable to Cross Site Scripting (XSS) in the markdown type note. This leads to remote code execution with payload : <video src=x onerror=(function(){require('child_process').exec('calc');})();>
- 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.