Discourse Theme (DiscoTOC) XSS via arbitrary HTML injection: CVE-2022-39270 October 2022

Arbitrary HTML injection in table-of-contents theme component in DiscoTOC
DiscoTOC is a Discourse theme component that generates a table of contents for topics. Users that can create topics in TOC-enabled categories (and have sufficient trust level - configured in component's settings) are able to inject arbitrary HTML on that topic's page. The issue has been fixed on the `main` branch. Admins can update the theme component through the admin UI (Customize -> Themes -> Components -> DiscoTOC -> Check for Updates). Alternatively, admins can temporarily disable the DiscoTOC theme component.

Vulnerability Analysis

CVE-2022-39270 is exploitable with network access, requires user interaction and a small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.

Attack Vector:

NETWORK

Attack Complexity:

LOW

Privileges Required:

LOW

User Interaction:

REQUIRED

Scope:

CHANGED

Confidentiality Impact:

LOW

Integrity Impact:

LOW

Availability Impact:

NONE

Weakness Type

What is a XSS Vulnerability?

The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

CVE-2022-39270 has been classified to as a XSS vulnerability or weakness.

Products Associated with CVE-2022-39270

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Affected Versions

Exploit Probability

EPSS

0.21%

Percentile

43.63%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.