CVE-2017-2520 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. iOS before 10.3.2 is affected. macOS before 10.12.5 is affected. tvOS before 10.2.1 is affected. watchOS before 3.2.2 is affected. The issue involves the "SQLite" component. It allows remote attackers to execute arbitrary code or cause a denial of service (buffer overflow and application crash) via a crafted SQL statement.
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Analysis
by VulDB Data Team • 12/24/2020
The vulnerability identified as CVE-2017-2520 represents a critical buffer overflow flaw within Apple's SQLite database implementation across multiple operating systems. This vulnerability affects iOS versions prior to 10.3.2, macOS versions prior to 10.12.5, tvOS versions prior to 10.2.1, and watchOS versions prior to 3.2.2. The flaw resides in the SQLite component that Apple incorporates into their ecosystem, making it a widespread concern across all Apple devices that utilize this database engine for various applications and system functions.
The technical nature of this vulnerability stems from improper input validation within the SQLite parser when processing specially crafted SQL statements. Attackers can exploit this buffer overflow by constructing malicious SQL queries that exceed the allocated buffer space, leading to memory corruption that can be leveraged for arbitrary code execution. The vulnerability manifests through the SQLite engine's handling of malformed input, where insufficient bounds checking allows attackers to overwrite adjacent memory locations. This type of flaw aligns with CWE-121, which describes buffer overflow conditions where insufficient space is allocated for data, and also relates to CWE-787, which covers out-of-bounds write vulnerabilities. The exploitation potential extends beyond simple code execution to include denial of service scenarios where applications crash due to the buffer overflow conditions.
The operational impact of CVE-2017-2520 is significant given the widespread use of Apple's SQLite implementation across their ecosystem. Since SQLite is embedded in numerous applications and system components, a successful exploitation could compromise the entire device or application stack. The vulnerability creates a persistent threat vector that remote attackers can leverage without requiring local access, making it particularly dangerous in environments where Apple devices are connected to untrusted networks. The potential for privilege escalation exists through the arbitrary code execution capability, which could allow attackers to gain elevated privileges within the affected system. This vulnerability directly maps to ATT&CK technique T1059.007 for command and scripting interpreter, where an attacker could use the vulnerability to execute malicious code on target systems.
Mitigation strategies for this vulnerability require immediate deployment of Apple's security updates, specifically iOS 10.3.2, macOS 10.12.5, tvOS 10.2.1, and watchOS 3.2.2, which contain patches addressing the buffer overflow conditions in the SQLite implementation. Organizations should implement network monitoring to detect potential exploitation attempts through malformed SQL queries, particularly in environments where Apple devices connect to external networks. Additionally, security teams should consider implementing application whitelisting policies that restrict execution of untrusted SQL queries, and conduct regular vulnerability assessments to identify systems running vulnerable versions of Apple operating systems. The patch addresses the root cause by implementing proper bounds checking and memory allocation controls within the SQLite parsing engine, preventing the buffer overflow conditions that enabled arbitrary code execution and denial of service attacks.