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Cross-site Scripting (XSS) possible with maliciously formed HTML attribute names and values in Phlex

High severity GitHub Reviewed Published Mar 11, 2024 in phlex-ruby/phlex • Updated Mar 14, 2024

Package

bundler phlex (RubyGems)

Affected versions

= 1.9.0
>= 1.8.0, < 1.8.2
= 1.7.0
>= 1.6.0, < 1.6.2
>= 1.5.0, < 1.5.2
= 1.4.0
>= 1.3.0, < 1.3.3
>= 1.2.0, < 1.2.2
= 1.1.0
< 1.0.1

Patched versions

1.9.1
1.8.2
1.7.1
1.6.2
1.5.2
1.4.1
1.3.3
1.2.2
1.1.1
1.0.1

Description

There is a potential cross-site scripting (XSS) vulnerability that can be exploited via maliciously crafted user data. This was due to improper case-sensitivity in the code that was meant to prevent these attacks.

Impact

If you render an <a> tag with an href attribute set to a user-provided link, that link could potentially execute JavaScript when clicked by another user.

a(href: user_profile) { "Profile" }

If you splat user-provided attributes when rendering any HTML or SVG tag, malicious event attributes could be included in the output, executing JavaScript when the events are triggered by another user.

h1(**JSON.parse(user_attributes))

Patches

Patches are available on RubyGems for all 1.x minor versions. The patched versions are:

If you are on main, it has been patched since aa50c60

Workarounds

Configuring a Content Security Policy that does not allow unsafe-inline would effectively prevent this vulnerability from being exploited.

References

In addition to upgrading to a patched version of Phlex, we strongly recommend configuring a Content Security Policy header that does not allow unsafe-inline. Here’s how you can configure a Content Security Policy header in Rails. https://guides.rubyonrails.org/security.html#content-security-policy-header

References

@joeldrapper joeldrapper published to phlex-ruby/phlex Mar 11, 2024
Published by the National Vulnerability Database Mar 11, 2024
Published to the GitHub Advisory Database Mar 12, 2024
Reviewed Mar 12, 2024
Last updated Mar 14, 2024

Severity

High

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
Unchanged
Confidentiality
High
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:U/C:H/I:L/A:N

EPSS score

0.045%
(17th percentile)

Weaknesses

CVE ID

CVE-2024-28199

GHSA ID

GHSA-242p-4v39-2v8g

Source code

Credits

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