Is CVE-2021-4295 actively exploited?

No active exploitation of CVE-2021-4295 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-4295 be exploited remotely?

Yes. CVE-2021-4295 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-4295?

CVE-2021-4295 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2021-4295

CWE-611Published: December 29, 2022· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

A vulnerability classified as problematic was found in ONC code-validator-api up to 1.0.30. This vulnerability affects the function vocabularyValidationConfigurations of the file src/main/java/org/sitenv/vocabularies/configuration/CodeValidatorApiConfiguration.java of the component XML Handler. The manipulation leads to xml external entity reference. Upgrading to version 1.0.31 is able to address this issue. The name of the patch is fbd8ea121755a2d3d116b13f235bc8b61d8449af. It is recommended to upgrade the affected component. VDB-217018 is the identifier assigned to this vulnerability.

NVD Source

Risk Analysis

The ONC code-validator-api is vulnerable to XML External Entity (XXE) injection, which can be exploited to access sensitive files or perform network attacks. The 9.8 CVSS score reflects the critical impact of this vulnerability.

No public exploit is known, and it is not in the CISA KEV. The vulnerability is remotely exploitable.

Recommended Action

Upgrade the code-validator-api component to version 1.0.31 or apply the patch fbd8ea121755a2d3d116b13f235bc8b61d8449af.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-4295 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.