Cyber Resilience

CVE-2023-41362

RCE in Mybb ≤ 1.8.36

Published
29 August 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 7.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.016 74th percentile
Risk Priority 67 floored blend · peak EPSS

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, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 26% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1059.002 AppleScript Execution
Adversaries may abuse AppleScript for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.005 Visual Basic Execution
Adversaries may abuse Visual Basic (VB) for execution.
T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-23335Same product: Mybb Mybb
CVE-2023-53979Same product: Mybb Mybb
CVE-2025-29457Same product: Mybb Mybb
CVE-2025-29460Same product: Mybb Mybb
CVE-2024-23336Same product: Mybb Mybb
CVE-2025-48940Same product: Mybb Mybb
CVE-2025-29459Same product: Mybb Mybb
CVE-2025-29458Same product: Mybb Mybb
CVE-2024-52702Same product: Mybb Mybb
CVE-2023-45556Same product: Mybb Mybb

Affected Assets

mybb
mybb
≤ 1.8.36

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.1

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.

addresses: CWE-94

Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.

addresses: CWE-94

Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.

addresses: CWE-94

Validates inputs used in dynamic code generation to block injected directives.

addresses: CWE-94

Directly prevents execution of attacker-supplied code written into data memory regions.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly target injection flaws via secure coding and testing (mostly), yet as a single broad outcome it leaves many code-generation specifics unaddressed (partial).

PR.DS-10 none match
prevents

PR.DS-10 protects runtime data confidentiality/integrity but has no bearing on neutralizing externally influenced input during code generation, so neither direction shows any preventive effect.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Banning unapproved code samples and unauthenticated web services, combined with secure-coding standards and SAST, prevents the dynamic generation or inclusion of attacker-supplied code.

none

Controls that restrict unauthorized or malicious code from being introduced via external networks or removable media limit opportunities for an attacker to inject and execute arbitrary code.

References