Skip to content

SilverStripe XXE Vulnerability in CSSContentParser

Moderate severity GitHub Reviewed Published May 24, 2022 to the GitHub Advisory Database • Updated Apr 25, 2024

Package

composer silverstripe/framework (Composer)

Affected versions

>= 4.0.0, < 4.7.4

Patched versions

4.7.4

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]).

References

Published by the National Vulnerability Database Jun 8, 2021
Published to the GitHub Advisory Database May 24, 2022
Reviewed Apr 25, 2024
Last updated Apr 25, 2024

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

EPSS score

0.100%
(43rd percentile)

Weaknesses

CVE ID

CVE-2020-25817

GHSA ID

GHSA-3vjc-5x79-m9r8

Source code

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.