CVE-2021-3767
Published: 06 September 2021
Summary
CVE-2021-3767 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Bookstackapp Bookstack. Its CVSS base score is 5.4 (Medium).
Operationally, ranked at the 49.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-27036
Vulnerability details
bookstack is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- 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.