CVE-2020-25817

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]).

How to fix CVE-2020-25817

To remediate CVE-2020-25817, upgrade the affected package to a fixed version below.

• —upgrade to 4.6.0 or later
• —upgrade to 4.7.4 or later

Is CVE-2020-25817 being exploited?

Low — EPSS is 0.3%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 4.6.0 | >= 4.6.0-rc1, <= 4.6.0-rc1
• >= 4.0.0, < 4.7.4

CVSS scores

References (8)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2020-25817
• PATCHgithub.com/silverstripe/silverstripe-framework
• WEBforum.silverstripe.org/c/releases
• WEBwww.silverstripe.org/blog/tag/release
• WEB