CVE-2010-4625 in MyBB
Summary
by MITRE
MyBB (aka MyBulletinBoard) before 1.4.12 does not properly handle a configuration with a visible forum that contains hidden threads, which allows remote attackers to obtain sensitive information by reading the Latest Threads block of the Portal Page.
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Analysis
by VulDB Data Team • 10/07/2021
The vulnerability identified as CVE-2010-4625 affects MyBulletinBoard versions prior to 1.4.12 and represents a significant information disclosure flaw that undermines the platform's access control mechanisms. This weakness specifically manifests when the forum configuration includes visible forums that contain hidden threads, creating a scenario where unauthorized users can bypass normal access restrictions through the portal page's Latest Threads block. The issue stems from inadequate input validation and access control enforcement within the forum's display logic, allowing attackers to retrieve thread information that should remain restricted to authorized users only. This vulnerability operates under the broader category of improper access control as defined by CWE-284, where the system fails to properly enforce access restrictions on resources that should be protected from unauthorized access. The attack vector is particularly concerning because it leverages the platform's own display functionality to expose sensitive information, making it difficult to detect through conventional security monitoring approaches.
The technical implementation of this vulnerability exploits the way MyBB handles thread visibility states during portal page rendering. When a forum is configured as visible but contains threads marked as hidden or restricted, the system fails to properly filter the thread data before displaying it in the Latest Threads block. This misconfiguration allows attackers to access thread titles, content previews, or metadata that should only be available to users with appropriate permissions. The flaw demonstrates a classic case of inadequate privilege checking in the user interface layer, where the application assumes that visible forums inherently allow access to all contained threads regardless of their individual permission settings. This behavior directly violates the principle of least privilege and creates an information leakage channel that can expose confidential discussions, private messages, or sensitive content that administrators intended to keep restricted to specific user groups. The vulnerability aligns with ATT&CK technique T1213.002 for Data from Information Repositories, as it enables unauthorized data extraction from the forum's information repository through legitimate user interface components.
The operational impact of CVE-2010-4625 extends beyond simple information disclosure to potentially compromise the integrity and confidentiality of forum communications. Attackers can gather intelligence about user activities, identify sensitive topics being discussed, and potentially discover usernames, posting patterns, or content that may be used for social engineering attacks. The vulnerability affects all users who can access the portal page, including anonymous visitors and unauthenticated users, making it particularly dangerous for forums containing sensitive business discussions, personal communications, or confidential administrative matters. Organizations relying on MyBB for internal communications or community platforms may experience significant reputational damage if this vulnerability is exploited to expose private conversations or sensitive information. The exploitation requires minimal technical skill and can be automated, making it a particularly attractive target for threat actors seeking to gather intelligence from web applications. This vulnerability also highlights the importance of proper access control implementation in web applications and demonstrates how seemingly benign configuration options can create security weaknesses when not properly validated against access control policies.
Mitigation strategies for CVE-2010-4625 should focus on implementing proper access control checks before displaying thread information in portal pages. The most effective immediate solution involves upgrading to MyBB version 1.4.12 or later, which includes patches addressing the improper access control logic. Organizations should also implement additional monitoring to detect unusual access patterns to portal pages and consider disabling or restricting the Latest Threads block for anonymous users. Configuration reviews should ensure that forums with sensitive content are properly restricted and that the visibility settings are consistently applied across all display components. Network-level controls such as web application firewalls can help detect and block exploitation attempts, while regular security assessments should verify that access control mechanisms function correctly across all forum components. The vulnerability serves as a reminder of the critical importance of validating access control decisions at every layer of application logic and demonstrates how information disclosure vulnerabilities can be leveraged to gain deeper insights into system operations and user activities.