MyBB Cross-Poster <= 1.0 - Authenticated (Admin+) Stored Cross-Site Scripting

2021-10-14 00:00

Thinkland Security Team

Strategic Overview

Status

Unpatched

Affected PluginMyBB Cross-Poster

Affected Version<= 1.0

CVSS5.5Medium

CVECVE-2021-39338

View all MyBB Cross-Poster vulnerabilities

Vulnerability Overview

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.

Technical Analysis

REMEDIATION: No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement. --- IDENTIFIER: CWE-79 (Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) The product 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.

External References

https://www.cve.org/CVERecord?id=CVE-2021-39338 https://www.wordfence.com/threat-intel/vulnerabilities/id/c6b079f5-715d-4fb3-bcaf-539412d5e956

CVSS Vector

5.5

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

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone

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