Cyber Resilience

CVE-2021-23899

Critical

Published: 13 January 2021

Published
13 January 2021
Modified
21 November 2024
KEV Added
—
Patch
—
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0044 63.8th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-23899 is a critical-severity Improper Restriction of XML External Entity Reference (CWE-611) vulnerability in Owasp Json-Sanitizer. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 36.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

OWASP json-sanitizer before 1.2.2 may emit closing SCRIPT tags and CDATA section delimiters for crafted input. This allows an attacker to inject arbitrary HTML or XML into embedding documents.

CWE(s)
CWE-611

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

owasp
json-sanitizer
≤ 1.2.2

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-611

Penetration testing includes XML external entity payloads, detecting XXE vulnerabilities and enabling their mitigation.

SI-4 System Monitoring
addresses: CWE-611

Identifies XML external entity processing via monitoring of unusual file/network access or resource usage.

References