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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-43281- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-94
- Updated
- 2026-11-02
CVE ListNo score
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.
- Record
CVE-2021-43281- Updated
- 2026-11-02
EUVDEUVD-2021-30225No score
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.
- Record
EUVD-2021-30225- Updated
- 2026-11-03
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-43281 is a high vulnerability (CVSS 7.2) in Mybb, published November 4, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.33%, the 71st percentile. No source names a fixed version.