CVE-2022-22626 in macOS
Summary
by MITRE • 03/18/2022
An out-of-bounds read was addressed with improved bounds checking. This issue is fixed in macOS Big Sur 11.6.5, macOS Monterey 12.3, Security Update 2022-003 Catalina. Processing a maliciously crafted AppleScript binary may result in unexpected application termination or disclosure of process memory.
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Analysis
by VulDB Data Team • 03/18/2022
This vulnerability represents a classic out-of-bounds read flaw that was addressed through enhanced bounds checking mechanisms within Apple's operating system components. The issue manifests when processing maliciously crafted AppleScript binary files, where improper input validation allows attackers to access memory locations beyond the intended buffer boundaries. Such vulnerabilities typically arise from insufficient boundary checks during array or buffer operations, creating opportunities for unauthorized memory access patterns that can lead to either application crashes or information disclosure.
The technical implementation of this flaw falls under CWE-129 which specifically addresses insufficient checking for bounds of an array data structure, making it a direct descendant of improper input validation issues. When an AppleScript binary contains crafted malicious content, the system's script processing engine fails to properly validate array indices or buffer limits before accessing memory locations, potentially allowing attackers to traverse beyond allocated memory regions. This type of vulnerability is particularly concerning in scripting environments where complex data structures are manipulated during execution.
The operational impact of this vulnerability extends beyond simple application instability to potentially enable more sophisticated attacks. When applications terminate unexpectedly due to out-of-bounds reads, it can provide attackers with information about the memory layout or even facilitate information disclosure attacks that reveal sensitive process memory contents. This memory exposure could potentially contain cryptographic keys, user credentials, or other confidential data depending on the context in which the vulnerable code executes. The vulnerability affects multiple macOS versions and was remediated through security updates that implemented stricter bounds checking mechanisms.
From an attack perspective, this vulnerability maps to several ATT&CK techniques including T1059.007 for AppleScript execution and potentially T1068 for privilege escalation if memory disclosure leads to credential exposure. The exploitability of such vulnerabilities often depends on the attacker's ability to craft malicious AppleScript files that can be executed within the target environment, typically through social engineering or exploitation of user interaction scenarios.
Mitigation strategies should focus on applying the available security updates immediately across all affected macOS versions including Big Sur 11.6.5, Monterey 12.3, and the Security Update 2022-003 for Catalina. Additional protective measures include implementing strict script execution policies that limit AppleScript processing capabilities, employing sandboxing mechanisms to contain potential memory access violations, and monitoring for unusual application termination patterns that might indicate exploitation attempts. Organizations should also consider restricting user privileges when executing scripts and implementing comprehensive endpoint detection and response solutions that can identify anomalous memory access patterns associated with such vulnerabilities.
The remediation approach demonstrates Apple's standard security posture of addressing memory safety issues through improved bounds checking mechanisms, which aligns with industry best practices for preventing buffer overflow and out-of-bounds read scenarios. This vulnerability type serves as a reminder of the critical importance of robust input validation in system components that process user-supplied data, particularly in scripting environments where complex data structures are manipulated during execution. The fix implemented represents a fundamental improvement to memory safety controls that helps prevent both denial of service conditions and potential information disclosure attacks that could compromise system integrity.