CVE-2026-111834 in Mang Board Plugin
Summary
by MITRE • 10/22/2026
Unrestricted Upload of File with Dangerous Type vulnerability in Kitae Park Mang Board WP mangboard allows Upload a Web Shell to a Web Server.This issue affects Mang Board WP: from n/a through 2.4.4.
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Analysis
by VulDB Data Team • 10/22/2026
The vulnerability identified as an Unrestricted Upload of File with Dangerous Type within the Mang Board WordPress plugin, specifically affecting versions up to and including 2.4.4, represents a critical security flaw that compromises the integrity of web servers hosting vulnerable installations. This issue stems from insufficient validation mechanisms during the file upload process, allowing attackers to bypass standard restrictions on accepted file types. By exploiting this weakness, an adversary can successfully upload malicious scripts, commonly referred to as web shells, directly onto the target server's directory structure where they are executable by the web service.
From a technical perspective, the core flaw lies in the application’s failure to enforce strict allowlists for uploaded content or to adequately sanitize file extensions and MIME types before storage. In many WordPress environments, upload directories may have execution permissions enabled for certain script languages such as PHP. When an attacker uploads a file with a dangerous extension like .php, .phtml, or similar executable formats without proper verification, the web server treats this uploaded artifact as legitimate code rather than static data. This misclassification enables the remote execution of arbitrary commands under the context of the web service user account, which often possesses elevated privileges relative to other application components.
The operational impact of this vulnerability is severe and multifaceted. Once a web shell is successfully deployed, it serves as a persistent backdoor that grants attackers interactive access to the underlying operating system. This capability allows for comprehensive data exfiltration, including sensitive user credentials, database contents, and proprietary business information stored within the WordPress environment. Furthermore, compromised servers are frequently repurposed as launchpads for further attacks against internal network resources or other external targets, facilitating lateral movement and botnet recruitment activities. The presence of such a backdoor also undermines trust in the application’s security posture, potentially leading to significant reputational damage and regulatory non-compliance depending on the nature of the data involved.
This vulnerability aligns with CWE-434, which describes Unrestricted Upload of File with Dangerous Type, highlighting the fundamental failure to restrict file types that can be uploaded by users. In terms of offensive security frameworks, this exploit maps directly to MITRE ATT&CK technique T1505.003, known as Web Shell: Server Side Script, and falls under the broader category of Initial Access via Vulnerable Components or User-Facing Application. The attack vector typically involves a remote attacker interacting with the public-facing upload interface, requiring no prior authentication if the vulnerability exists in an unauthenticated endpoint, thereby increasing its exploitability across diverse environments.
Mitigation strategies must prioritize immediate remediation through software updates and robust configuration hardening. Administrators should upgrade Mang Board WP to version 2.4.5 or later as soon as possible, where developers have presumably addressed these input validation gaps. In cases where updating is not immediately feasible, temporary mitigations include disabling file upload functionality entirely if it is not essential for business operations, implementing strict server-level restrictions on executable permissions within the WordPress uploads directory to prevent script execution, and deploying a Web Application Firewall configured with rulesets that detect and block common web shell patterns or anomalous POST requests containing suspicious file extensions. Regular auditing of uploaded files and monitoring for unusual outbound network traffic can also aid in early detection of exploitation attempts.