CVE-2021-39338 Information

Description

The MyBB Cross-Poster WordPress plugin is vulnerable to Stored Cross-Site Scripting due to insufficient input validation and sanitization via several parameters found in the ~/classes/MyBBXPSettings.php file which allowed attackers with administrative user access to inject arbitrary web scripts in versions up to and including 1.0. This affects multi-site installations where unfiltered_html is disabled for administrators and sites where unfiltered_html is disabled.

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Reference

https://github.com/BigTiger2020/word-press/blob/main/MyBB%20Cross-Poster.md https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39338 https://plugins.trac.wordpress.org/browser/mybb-cross-poster/trunk/classes/MyBBXPSettings.php

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

REQUIRED

Confidentiality Impact

CHANGED

Integrity Impact

LOW

Availability Impact

LOW

Base Score

NONE

Base Severity

4.8