CVE-2020-13632 in SQLite
Summary
by MITRE
ext/fts3/fts3_snippet.c in SQLite before 3.32.0 has a NULL pointer dereference via a crafted matchinfo() query.
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Analysis
by VulDB Data Team • 05/21/2025
The vulnerability identified as CVE-2020-13632 represents a critical NULL pointer dereference flaw within the SQLite database engine's Full Text Search implementation. This issue specifically affects the fts3_snippet.c module and occurs when processing crafted matchinfo() queries against SQLite versions prior to 3.32.0. The vulnerability stems from inadequate input validation and error handling within the full-text search functionality that processes query results for snippet generation.
The technical exploitation of this vulnerability requires an attacker to construct a malicious matchinfo() query that triggers a NULL pointer dereference during the snippet generation process. This occurs when the FTS3 (Full Text Search 3) module attempts to access memory locations that have not been properly initialized or validated. The flaw manifests during the execution of database queries that utilize the matchinfo() function, which is designed to provide information about query matching for full-text search operations. When the query processing encounters specific patterns in the search terms or document structure, the internal state management fails to properly handle NULL references, leading to a crash of the database process.
The operational impact of CVE-2020-13632 extends beyond simple denial of service scenarios as it can potentially enable more sophisticated attacks depending on the deployment environment. Database servers running vulnerable SQLite versions are susceptible to remote code execution if the application allows untrusted input to be processed through database queries. The vulnerability affects any system where SQLite is used for full-text search capabilities, including web applications, mobile applications, and embedded systems that rely on SQLite's FTS3 functionality. This includes numerous applications that utilize SQLite for local data storage and search functionality, making the attack surface particularly broad across different software ecosystems.
Security practitioners should prioritize patching affected systems with SQLite version 3.32.0 or later, which includes the necessary fixes for this NULL pointer dereference issue. The vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions in software implementations. From an adversarial perspective, this vulnerability maps to ATT&CK technique T1059.002 for command and control communication, as attackers could potentially use the crash conditions to disrupt services or as a stepping stone for further exploitation. Organizations should implement input sanitization measures for all database queries involving full-text search functions and consider monitoring for unusual query patterns that might indicate exploitation attempts. Additionally, the fix implemented in SQLite 3.32.0 demonstrates proper error handling mechanisms that validate pointer states before dereferencing, aligning with secure coding practices recommended for preventing memory safety vulnerabilities in database engines.