CVE-2005-3777 in MyBB
Summary
by MITRE
MyBulletinBoard (MyBB) 1.0 PR2 Rev 686 allows remote attackers to delete or move private messages (PM) via modified fields in the inbox form.
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Analysis
by VulDB Data Team • 04/30/2019
The vulnerability identified as CVE-2005-3777 affects MyBulletinBoard version 1.0 PR2 Rev 686, a popular web-based bulletin board system that was widely used for online community discussions and forums. This security flaw represents a critical authorization bypass issue that directly impacts the integrity and confidentiality of private messaging functionality within the platform. The vulnerability specifically targets the inbox form processing mechanism, which handles user interactions with private messages, creating a significant risk for users who rely on the private messaging system for sensitive communications.
The technical implementation of this vulnerability stems from insufficient input validation and improper access control mechanisms within the MyBB application's message handling components. Attackers can exploit this weakness by crafting specially modified HTTP requests that manipulate form fields intended for private message operations. The vulnerability occurs during the processing of inbox form submissions where the application fails to properly verify user permissions or validate the authenticity of message identifiers and action parameters. This allows malicious actors to submit modified requests that instruct the system to delete or move private messages belonging to other users without proper authorization, effectively bypassing the application's built-in security controls.
The operational impact of CVE-2005-3777 extends beyond simple data manipulation, as it fundamentally compromises the privacy and trust associated with private messaging systems within the MyBB platform. An attacker who successfully exploits this vulnerability can not only delete private messages but also move them to different folders or locations, potentially obscuring evidence of their actions or disrupting the normal workflow of legitimate users. This capability enables a range of malicious activities including message deletion for the purpose of hiding evidence of inappropriate communications, unauthorized access to sensitive information shared through private messages, and potential disruption of community discussions. The vulnerability affects all users who have access to the private messaging functionality, creating a broad attack surface that could impact thousands of forum users depending on the platform's deployment size.
This vulnerability aligns with CWE-285, which addresses improper authorization issues in software systems, and demonstrates how inadequate access control validation can lead to privilege escalation and unauthorized data manipulation. From an attacker's perspective, this represents a low-effort, high-impact vector that can be automated and scaled across multiple forum instances. The attack pattern corresponds to techniques described in the ATT&CK framework under privilege escalation and credential access categories, specifically targeting the application layer where user permissions are enforced. Organizations deploying MyBB systems should consider this vulnerability as part of a broader security assessment, particularly given that the affected version was released in 2005 and likely lacked modern security hardening practices that would prevent such input validation failures.
Mitigation strategies for CVE-2005-3777 require immediate implementation of proper input validation and access control mechanisms within the MyBB application. System administrators should ensure that all user inputs, particularly those related to message operations, are properly sanitized and validated against expected parameter formats. The application should enforce strict authorization checks that verify the authenticated user's ownership of target messages before permitting deletion or movement operations. Additionally, implementing proper session management and request validation techniques would prevent attackers from submitting forged requests with modified form fields. Organizations should also consider implementing logging mechanisms that track private message operations, enabling detection of unauthorized activities and providing forensic capabilities for incident response. The most effective long-term solution involves upgrading to supported versions of MyBB that have addressed this vulnerability through proper security hardening and input validation procedures.