CVE-2020-25817

Name: CVE-2020-25817
Creator: NVD / NIST
Published: 2021-06-08T18:15:07.907+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.8/10EPSS 0.82%

Last modified Jun 17, 2026

CVE-2020-25817 is a medium-severity vulnerability rated 4.8/10 on the CVSS scale. SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. EPSS estimates a 0.82% chance of exploitation in the next 30 days.

Description

SilverStripe through 4.6.0-rc1 has an XXE Vulnerability in CSSContentParser. A developer utility meant for parsing HTML within unit tests can be vulnerable to XML External Entity (XXE) attacks. When this developer utility is misused for purposes involving external or user submitted data in custom project code, it can lead to vulnerabilities such as XSS on HTML output rendered through this custom code. This is now mitigated by disabling external entities during parsing. (The correct CVE ID year is 2020 [CVE-2020-25817, not CVE-2021-25817]).

Metrics

CVSS 3.1

4.8/10

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

EPSS Probability

0.82%

52.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-611

Affected Software

Vendor	Product	Versions	Update
Silverstripe	Silverstripe	< 4.6.0	—
Silverstripe	Silverstripe	4.6.0	Rc1

References

https://forum.silverstripe.org/c/releasesRelease Notes, Vendor Advisory
https://www.silverstripe.org/blog/tag/releaseRelease Notes, Vendor Advisory
https://www.silverstripe.org/download/security-releases/Vendor Advisory
https://www.silverstripe.org/download/security-releases/cve-2020-25817Broken Link
https://forum.silverstripe.org/c/releasesRelease Notes, Vendor Advisory
https://www.silverstripe.org/blog/tag/releaseRelease Notes, Vendor Advisory
https://www.silverstripe.org/download/security-releases/Vendor Advisory
https://www.silverstripe.org/download/security-releases/cve-2020-25817Broken Link

Timeline

Published: Jun 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-25817?

How severe is CVE-2020-25817?

CVE-2020-25817 has a CVSS score of 4.8/10 (MEDIUM severity). The EPSS model estimates a 0.82% probability of exploitation in the next 30 days.

How do I fix CVE-2020-25817?

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-2020-25817?

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

Scan your code now

Source: NVD / NIST