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HTMLi(XSS without CSP) via Onebox urls

Moderate
jomaxro published GHSA-j855-mhxj-x6vg Feb 4, 2025

Package

Discourse (Discourse)

Affected versions

stable <= 3.3.3; beta <= 3.4.0.beta3; tests-passed <= 3.4.0.beta3

Patched versions

stable >= 3.3.4; beta >= 3.4.0.beta4; tests-passed >= 3.4.0.beta4

Description

Impact

An attacker can execute arbitrary JavaScript on users' browsers by posting a maliciously crafted onebox url. This issue only affects sites with CSP disabled.

Patches

This problem is patched in the latest version of Discourse.

Workarounds

Enable CSP, Disable inline Oneboxes globally, or allow specific domains for Oneboxing.

References

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
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
Low

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:N/S:U/C:L/I:N/A:L

CVE ID

CVE-2024-56328

Weaknesses

No CWEs