CVE-2011-1131 in SMF
Summary
by MITRE
The PlushSearch2 function in Search.php in Simple Machines Forum (SMF) before 1.1.13, and 2.x before 2.0 RC5, uses certain cached data in a situation where a temporary table has been created, even though this cached data is intended only for situations where a temporary table has not been created, which might allow remote attackers to obtain sensitive information via a search.
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Analysis
by VulDB Data Team • 02/09/2019
The vulnerability identified as CVE-2011-1131 affects Simple Machines Forum versions prior to 1.1.13 and 2.x versions before 2.0 RC5, specifically within the PlushSearch2 function in the Search.php file. This represents a critical information disclosure flaw that stems from improper handling of cached data during search operations. The vulnerability occurs when the system creates a temporary table for search processing but subsequently fails to properly distinguish between cached data that is valid for temporary table scenarios versus scenarios where no temporary table exists. This fundamental mismanagement of cached data contexts creates an exploitable condition where attackers can manipulate search queries to access sensitive information that should remain protected.
The technical implementation of this vulnerability involves a flawed conditional logic error in the search function's data handling mechanism. When SMF processes search queries, it maintains different cached datasets depending on whether temporary tables are created during the search operation. The PlushSearch2 function incorrectly references cached data intended for non-temporary table scenarios when temporary tables are actually in use. This mismatch allows attackers to craft specific search parameters that trigger the retrieval of cached data meant for different operational contexts, potentially exposing user information, session data, or other sensitive elements that should not be accessible through normal search operations. The vulnerability specifically manifests when the system attempts to optimize search performance by utilizing cached results, but fails to properly validate the operational context before utilizing these cached resources.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. Remote attackers can exploit this weakness to gather sensitive user information including but not limited to user profiles, private messages, and potentially session identifiers that could facilitate further exploitation. The vulnerability affects the core search functionality of the forum, making it accessible to any authenticated or unauthenticated user who can submit search queries. Given that forums typically contain large amounts of user-generated content and personal information, the potential for data exposure is significant. This flaw essentially allows attackers to bypass normal access controls and retrieve information that should only be available to authorized users within specific operational contexts.
Mitigation strategies for CVE-2011-1131 focus primarily on updating to patched versions of Simple Machines Forum where the conditional logic error has been corrected. System administrators should immediately upgrade to SMF versions 1.1.13 or 2.0 RC5 and later, which contain the necessary fixes for proper cached data handling. Additionally, implementing network-level protections such as web application firewalls and rate limiting on search endpoints can provide additional defense in depth. The vulnerability aligns with CWE-200, which describes improper information disclosure, and relates to ATT&CK technique T1213, specifically data from information repositories, as attackers can systematically extract sensitive information from the forum's search functionality. Organizations should also consider implementing database query monitoring to detect unusual search patterns that might indicate exploitation attempts, and establish proper access controls for search functions to limit information exposure even in unpatched environments.