CVE-2024-23335 in MyBB
Summary
by MITRE • 05/01/2024
MyBB is a free and open source forum software. The backup management module of the Admin CP may accept `.htaccess` as the name of the backup file to be deleted, which may expose the stored backup files over HTTP on Apache servers. MyBB 1.8.38 resolves this issue. Users are advised to upgrade. There are no known workarounds for this vulnerability
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/30/2025
The vulnerability identified as CVE-2024-23335 affects MyBB, a widely used open source forum software platform that serves millions of users across various online communities. This security flaw resides within the backup management functionality of the Admin Control Panel, specifically in how the system handles file deletion operations. The issue represents a critical oversight in input validation and file system access controls that could potentially compromise the confidentiality and integrity of backed up data. The vulnerability impacts versions prior to 1.8.38, making it essential for administrators to assess their current deployment status and implement necessary upgrades to maintain system security.
The technical exploitation of this vulnerability stems from improper validation of backup file names within the administrative interface. When administrators attempt to delete backup files through the backup management module, the system accepts the filename `.htaccess` as a legitimate backup file name for deletion. This seemingly innocuous filename manipulation creates a dangerous scenario where the system's file handling logic inadvertently removes the `.htaccess` file from the web server's document root. The `.htaccess` file typically contains critical server configuration directives that control access permissions, security settings, and file access rules on Apache servers. When this file is removed, it can expose previously stored backup files that would normally be protected by server-level access controls, allowing unauthorized users to access sensitive data through HTTP requests.
The operational impact of this vulnerability extends beyond simple file deletion, creating a significant security risk for organizations relying on MyBB for their forum infrastructure. When the `.htaccess` file is removed, it can result in the exposure of backup files that contain sensitive user data, forum configurations, and potentially system credentials. This exposure occurs because Apache servers typically use `.htaccess` files to enforce access restrictions and prevent direct HTTP access to certain directories or file types. Without proper access controls, backup files that might contain user information, private messages, or administrative configurations become accessible to any user with internet access to the forum's web server. The vulnerability essentially creates a backdoor that bypasses normal security mechanisms designed to protect sensitive data, making it particularly dangerous for forums handling confidential information or serving as platforms for communities with privacy concerns.
This vulnerability aligns with several cybersecurity standards and frameworks, particularly CWE-22 which addresses "Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')", and CWE-200 which covers "Information Exposure". The issue also relates to ATT&CK technique T1213.002 which describes "Data from Information Repositories" and T1566.001 which covers "Phishing via Service" as attackers could leverage the exposed backup files to gain further intelligence about the target system. The vulnerability demonstrates how seemingly minor input validation flaws can create significant security implications, particularly in administrative interfaces where privileged operations are performed. Organizations using MyBB should consider this vulnerability as part of their broader security posture assessment, especially when evaluating their backup management and file access controls. The lack of known workarounds for this specific vulnerability emphasizes the importance of immediate upgrade to version 1.8.38 or later, as no alternative mitigation strategies exist that would prevent the exploitation of this particular flaw without updating the core software components.