Vulnerability 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 Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mybb Cross-Poster Project | Mybb Cross-Poster | <= 1.0 |
Related Weaknesses (CWE)
References
- https://github.com/BigTiger2020/word-press/blob/main/MyBB%20Cross-Poster.mdExploitThird Party Advisory
- https://plugins.trac.wordpress.org/browser/mybb-cross-poster/trunk/classes/MyBBXPatchThird Party Advisory
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39338Third Party Advisory
- https://github.com/BigTiger2020/word-press/blob/main/MyBB%20Cross-Poster.mdExploitThird Party Advisory
- https://plugins.trac.wordpress.org/browser/mybb-cross-poster/trunk/classes/MyBBXPatchThird Party Advisory
- https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39338Third Party Advisory
FAQ
What is CVE-2021-39338?
CVE-2021-39338 is a vulnerability with a CVSS score of 5.5 (MEDIUM). 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.p...
How severe is CVE-2021-39338?
CVE-2021-39338 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-39338?
Check the references section above for vendor advisories and patch information. Affected products include: Mybb Cross-Poster Project Mybb Cross-Poster.