CVE-2023-41362
Published: 29 August 2023
Summary
CVE-2023-41362 is a high-severity Code Injection (CWE-94) vulnerability in Mybb Mybb. Its CVSS base score is 7.2 (High).
Operationally, ranked in the top 3.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
Deeper analysis
MyBB versions prior to 1.8.36 contain a code-injection vulnerability tracked as CVE-2023-41362 and assigned CWE-94. The forum software's Admin CP templates deliberately invoke PHP eval on user-supplied template content; although input validation was present, PHP type juggling in conjunction with PCRE matching allowed the checks to be bypassed, resulting in arbitrary code execution.
An attacker who already possesses high-privileged Admin CP credentials can exploit the flaw over the network without user interaction. Successful exploitation grants the ability to inject and execute arbitrary PHP, yielding full control over the confidentiality, integrity, and availability of the MyBB installation.
The MyBB project addressed the issue in release 1.8.36. A corresponding patch that strengthens the validation logic around eval input is available in the project's GitHub repository, and the GitHub Security Advisory GHSA-pr74-wvp3-q6f5 together with the vendor advisory at mybb.com/versions/1.8.36 provide upgrade guidance.
The associated EPSS score reached 0.2581 at disclosure and has remained at that level, indicating moderate but stable exploitation interest rather than a post-disclosure surge.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-45865
Vulnerability details
MyBB before 1.8.36 allows Code Injection by users with certain high privileges. Templates in Admin CP intentionally use eval, and there was some validation of the input to eval, but type juggling interfered with this when using PCRE within PHP.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.
Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.
Validates inputs used in dynamic code generation to block injected directives.
Directly prevents execution of attacker-supplied code written into data memory regions.