RCE in Mybb

CVE-2021-43281

MyBB before 1.8.29 allows Remote Code Injection by an admin with the "Can manage settings?" permission. The Admin CP's Settings management module does not validate setting types correctly on insertion and update, making it possible to add settings of supported type "php" with PHP code, executed on Change Settings pages.

Vulnerability class: RCE (Remote Code Execution)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (70.3th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-43281: held from 0.013 to 0.013.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-43281?
CVE-2021-43281 is a high-severity vulnerability in Mybb, classified under Code Injection. CVSS score: 7.2/10. Published 2021-11-04.
How severe is CVE-2021-43281?
High severity. CVSS v3 base score is 7.2 out of 10.