CVE-2020-21524

Name: CVE-2020-21524
Creator: NVD / NIST
Published: 2020-09-30T18:15:24.023+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 1.51%

Last modified Jun 17, 2026

CVE-2020-21524 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. There is a XML external entity (XXE) vulnerability in halo v1.1.3, The function of importing other blogs in the background(/api/admin/migrations/wordpress) needs to parse the xml file, but it is not used for security defense, This vulnerability can detect the intranet, read files, enable ddos attacks, etc. exp:https://github.com/halo-dev/halo/issues/423. EPSS estimates a 1.51% chance of exploitation in the next 30 days.

Description

There is a XML external entity (XXE) vulnerability in halo v1.1.3, The function of importing other blogs in the background(/api/admin/migrations/wordpress) needs to parse the xml file, but it is not used for security defense, This vulnerability can detect the intranet, read files, enable ddos attacks, etc. exp:https://github.com/halo-dev/halo/issues/423

Metrics

CVSS 3.1

9.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS Probability

1.51%

71.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-611

Affected Software

Vendor	Product	Versions
Halo	Halo	1.1.3

References

https://github.com/halo-dev/halo/issues/423Exploit, Issue Tracking, Third Party Advisory
https://github.com/halo-dev/halo/issues/423Exploit, Issue Tracking, Third Party Advisory

Timeline

Published: Sep 30, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-21524?

How severe is CVE-2020-21524?

CVE-2020-21524 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.51% probability of exploitation in the next 30 days.

How do I fix CVE-2020-21524?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-21524?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST