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Improper Neutralization of Invalid Characters in Data Attribute Names in org.xwiki.commons:xwiki-commons-xml

Critical
michitux published GHSA-pv7v-ph6g-3gxv May 9, 2023

Package

maven org.xwiki.commons:xwiki-commons-xml (Maven)

Affected versions

>= 14.6-rc-1, < 14.10.4

Patched versions

14.10.4, 15.0-rc-1

Description

Impact

The HTML sanitizer, introduced in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid data attributes. This can be exploited, e.g., via the link syntax in any content that supports XWiki syntax like comments in XWiki:

[[Link1>>https://XWiki.example.com||data-x/onmouseover="alert('XSS1')"]].

When a user moves the mouse over this link, the malicious JavaScript code is executed in the context of the user session. When this user is a privileged user who has programming rights, this allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance.

Note that this vulnerability does not affect restricted cleaning in HTMLCleaner as there attributes are cleaned and thus characters like / and > are removed in all attribute names.

Patches

This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by making sure that data attributes only contain allowed characters.

Workarounds

There are no known workarounds apart from upgrading to a version including the fix.

References

For more information

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Severity

Critical

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
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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:L/UI:R/S:C/C:H/I:H/A:H

CVE ID

CVE-2023-31126

Weaknesses