CVE-2021-1864 in watchOS
Summary
by MITRE • 09/08/2021
A use after free issue was addressed with improved memory management. This issue is fixed in iOS 14.5 and iPadOS 14.5, watchOS 7.4, tvOS 14.5. An attacker with JavaScript execution may be able to execute arbitrary code.
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Analysis
by VulDB Data Team • 06/06/2026
This vulnerability represents a classic use after free condition that was resolved through enhanced memory management protocols. The flaw emerged from improper handling of memory allocation and deallocation processes within Apple's operating systems, creating a scenario where freed memory blocks could still be accessed by malicious code. The issue affected multiple Apple platforms including iOS 14.5, iPadOS 14.5, watchOS 7.4, and tvOS 14.5, indicating a systemic problem within the memory management subsystem that required coordinated patching across the entire ecosystem.
The technical nature of this vulnerability aligns with CWE-416, which specifically addresses use after free conditions in memory management. When applications or system processes free memory blocks that are subsequently accessed by other code, attackers can exploit this window of opportunity to manipulate program execution flow. In this particular case, the vulnerability was reachable through JavaScript execution contexts, suggesting that the flaw existed within the web browser engine or JavaScript interpreter component of these operating systems. The attack vector demonstrates how modern web-based exploits can leverage memory corruption vulnerabilities to achieve privilege escalation and arbitrary code execution.
The operational impact of this vulnerability extends beyond simple code execution capabilities, as it provides attackers with a pathway to bypass security boundaries and potentially gain persistent access to affected devices. When an attacker can execute arbitrary code through JavaScript, they essentially gain control over the device's execution environment, allowing for data exfiltration, installation of additional malware, or modification of system behavior. This type of vulnerability is particularly concerning in mobile environments where devices store sensitive personal and corporate data, making the exploitation potential significant for both individual users and enterprise security.
Mitigation strategies for this vulnerability required immediate deployment of the security patches released by Apple in their respective operating system updates. Organizations should prioritize updating all affected devices to the patched versions of iOS 14.5, iPadOS 14.5, watchOS 7.4, and tvOS 14.5 to eliminate the risk of exploitation. Additional defensive measures include implementing network-based monitoring to detect suspicious JavaScript activity and maintaining robust endpoint protection solutions that can identify and block malicious code execution attempts. The vulnerability also highlights the importance of regular security assessments and vulnerability management programs that can quickly identify and remediate similar memory corruption issues. From an ATT&CK framework perspective, this vulnerability maps to techniques involving memory injection and privilege escalation, making it a critical target for both defensive and offensive security operations to address through proper patch management and runtime protection measures.