CVE-2020-13435 in iCloud
Summary
by MITRE
SQLite through 3.32.0 has a segmentation fault in sqlite3ExprCodeTarget in expr.c.
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Analysis
by VulDB Data Team • 01/23/2026
The vulnerability identified as CVE-2020-13435 represents a critical segmentation fault within the SQLite database engine version 3.32.0 and earlier. This flaw exists in the sqlite3ExprCodeTarget function located in the expr.c source file, which is a core component responsible for expression code generation and target handling within the SQL query processing pipeline. The issue manifests as a null pointer dereference or invalid memory access pattern that occurs during specific query compilation scenarios, particularly when processing complex expressions with nested subqueries or certain aggregate functions.
The technical root cause of this vulnerability stems from inadequate input validation and memory management within the expression code generation subsystem. When SQLite processes certain malformed or complex SQL queries, the sqlite3ExprCodeTarget function fails to properly handle edge cases in expression tree traversal, leading to a segmentation fault that crashes the database engine. This vulnerability falls under the CWE-125 vulnerability category, which describes out-of-bounds read conditions, and more specifically aligns with CWE-476 which covers null pointer dereference issues. The flaw demonstrates characteristics consistent with improper handling of expression evaluation contexts where the function attempts to access memory locations that have not been properly initialized or validated.
From an operational perspective, this vulnerability presents significant risks to applications and systems that rely on SQLite for data storage and retrieval. The segmentation fault can lead to complete application crashes, resulting in denial of service conditions that may affect database availability and data integrity. Attackers could potentially exploit this vulnerability through crafted SQL queries submitted to applications using SQLite, causing unauthorized service disruption or, in more sophisticated attack scenarios, potentially leading to remote code execution if the application does not properly sanitize input. The vulnerability impacts systems where SQLite is used as an embedded database engine, including mobile applications, web browsers, and various enterprise software solutions that depend on SQLite for local data persistence.
Mitigation strategies for CVE-2020-13435 should prioritize immediate patching of SQLite installations to version 3.32.1 or later, which contains the necessary fixes for the segmentation fault issue. Organizations should implement comprehensive input validation and sanitization measures for all SQL queries processed by applications using SQLite, particularly focusing on preventing malformed expressions from reaching the database engine. Additionally, deploying intrusion detection systems that monitor for unusual query patterns and implementing proper error handling and logging mechanisms can help detect potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique for application layer command and control, as it represents a potential vector for remote code execution through database engine exploitation. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable SQLite versions, while application developers should review their code for proper error handling and input validation to prevent exploitation of similar memory corruption vulnerabilities in their database interactions.