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By-passing Cross-Site Scripting Protection in HTML Sanitizer

Moderate
ohader published GHSA-47m6-46mj-p235 Sep 13, 2022

Package

composer typo3/html-sanitizer (Composer)

Affected versions

1.0.0-1.0.6, 2.0.0-2.0.15

Patched versions

1.0.7, 2.0.16

Description

Meta

  • CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C (5.7)

Problem

Due to a parsing issue in upstream package masterminds/html5, malicious markup used in a sequence with special HTML comments cannot be filtered and sanitized. This allows to by-pass the cross-site scripting mechanism of typo3/html-sanitizer.

Solution

Update to typo3/html-sanitizer versions 1.0.7 or 2.0.16 that fix the problem described.

Credits

Thanks to David Klein who reported this issue, and to TYPO3 security team member Oliver Hader who fixed the issue.

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
None
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:N/UI:R/S:C/C:L/I:L/A:N

CVE ID

CVE-2022-36020

Weaknesses

Credits