CVE-2018-20346 in macOS
Summary
by MITRE
SQLite before 3.25.3, when the FTS3 extension is enabled, encounters an integer overflow (and resultant buffer overflow) for FTS3 queries that occur after crafted changes to FTS3 shadow tables, allowing remote attackers to execute arbitrary code by leveraging the ability to run arbitrary SQL statements (such as in certain WebSQL use cases), aka Magellan.
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Analysis
by VulDB Data Team • 07/03/2023
The vulnerability identified as CVE-2018-20346 represents a critical security flaw in SQLite database systems affecting versions prior to 3.25.3. This issue specifically impacts systems utilizing the FTS3 full-text search extension, which is commonly employed in web applications and database systems where text search capabilities are required. The vulnerability stems from improper handling of integer overflow conditions within the FTS3 implementation, creating a scenario where malicious input can trigger buffer overflow conditions that ultimately enable arbitrary code execution. The flaw is particularly dangerous because it can be exploited through WebSQL interfaces where users have the ability to execute arbitrary SQL statements, making it a significant concern for web applications that rely on SQLite for data storage and retrieval operations.
The technical root cause of this vulnerability lies in the integer overflow condition that occurs when processing FTS3 queries following specific modifications to FTS3 shadow tables. These shadow tables are internal structures used by SQLite's FTS3 extension to maintain indexing information for full-text search operations. When crafted malicious input is processed through the FTS3 query mechanism, the integer overflow results in memory corruption that can be leveraged to overwrite critical memory locations. This memory corruption creates opportunities for attackers to inject and execute arbitrary code within the context of the SQLite process. The vulnerability is classified under CWE-190 as an integer overflow condition, which is a well-known class of security flaws that can lead to buffer overflows and subsequent code execution. The attack vector is particularly concerning because it requires only the ability to execute arbitrary SQL statements, which is commonly permitted in WebSQL environments where database operations are exposed directly to user input.
The operational impact of CVE-2018-20346 extends beyond simple data corruption or denial of service scenarios, as it enables full remote code execution capabilities for attackers who can manipulate FTS3 queries through WebSQL interfaces. This vulnerability affects web applications that utilize SQLite databases with FTS3 extensions, particularly those implementing WebSQL APIs where user input is not properly sanitized or validated. The exploitation requires minimal privileges and can be executed remotely, making it an attractive target for attackers seeking to compromise web applications. The vulnerability is particularly dangerous in environments where SQLite is used as a backend database for web applications, content management systems, or mobile applications where data persistence is critical. Attackers can leverage this vulnerability to gain complete control over affected systems, potentially leading to data theft, system compromise, or further lateral movement within network environments.
Organizations should implement immediate mitigations including upgrading to SQLite version 3.25.3 or later, which contains the necessary patches to address the integer overflow condition in FTS3 processing. Additionally, administrators should review and restrict SQL statement execution capabilities in WebSQL interfaces where possible, implementing proper input validation and sanitization measures. The mitigation strategy should also include monitoring for unusual database query patterns that might indicate exploitation attempts, as well as implementing network-level protections to detect and block malicious SQL injection attempts. Security teams should also consider implementing database activity monitoring solutions that can detect anomalous behavior in FTS3 query processing and shadow table modifications. Organizations utilizing affected SQLite versions should conduct thorough security assessments of their WebSQL implementations to identify potential exposure points and ensure that all applications using FTS3 extensions are properly updated to prevent exploitation. The vulnerability aligns with ATT&CK technique T1059.002 for command and script injection, as it enables attackers to execute arbitrary code through SQL statement manipulation.