Vulnerability in Halo

CVE-2020-21523

A Server-Side Freemarker template injection vulnerability in halo CMS v1.1.3 In the Edit Theme File function. The ftl file can be edited. This is the Freemarker template file. This file can cause arbitrary code execution when it is rendered in the background. exp: <#assign test="freemarker.template.utility.Execute"?new()> ${test("touch /tmp/freemarkerPwned")}

EPSS: 0.026 (83.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

  • Halo — versions 1.1.3
  • N/a — versions n/a

Weakness classification (CWE)

References

  • cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC, Issue Tracking)

Frequently asked questions

What is CVE-2020-21523?
CVE-2020-21523 is a critical-severity vulnerability in Halo, classified under Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection). CVSS score: 9.8/10. Published 2020-09-30.
How severe is CVE-2020-21523?
Critical severity. CVSS v3 base score is 9.8 out of 10.