CVE-2020-9983 in iCloud
Summary
by MITRE • 10/16/2020
An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in Safari 14.0. Processing maliciously crafted web content may lead to code execution.
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Analysis
by VulDB Data Team • 07/08/2025
The vulnerability identified as CVE-2020-9983 represents a critical out-of-bounds write flaw discovered in Apple Safari web browser versions prior to 14.0. This type of vulnerability falls under the category of memory safety issues and is particularly dangerous because it can be exploited to execute arbitrary code on affected systems. The flaw manifests when Safari processes maliciously crafted web content, potentially allowing remote attackers to gain control over the affected system. This vulnerability is classified under CWE-787, which specifically addresses out-of-bounds write conditions in software applications.
The technical nature of this vulnerability stems from insufficient bounds checking within Safari's web rendering engine. When processing web content that contains crafted malicious data structures, the browser fails to properly validate array indices or memory boundaries before writing data to memory locations. This allows an attacker to write data beyond the allocated memory buffer, potentially overwriting critical program data, function pointers, or return addresses. The exploitation of such a flaw typically follows the ATT&CK framework technique T1059.007, where adversaries leverage browser vulnerabilities to execute malicious code through web-based attacks.
The operational impact of CVE-2020-9983 is significant across enterprise and individual computing environments. Given Safari's widespread use on macOS and iOS devices, this vulnerability affects millions of users who may unknowingly encounter malicious web content during normal browsing activities. The remote code execution capability means that attackers could potentially install malware, steal sensitive data, or establish persistent access to compromised systems. Organizations with Safari-based workflows or those relying on web-based applications for business operations face heightened risk, particularly in environments where users may encounter untrusted web content.
Mitigation strategies for CVE-2020-9983 primarily focus on immediate software updates and browser security hardening. The most effective remediation is upgrading to Safari 14.0 or later versions where Apple has implemented improved bounds checking mechanisms to prevent the out-of-bounds write condition. Security administrators should also implement additional protective measures including web application firewalls, content filtering solutions, and browser security extensions that can help detect and block malicious web content. Regular security assessments and user education programs about safe browsing practices remain essential components of a comprehensive defense strategy against such vulnerabilities. The vulnerability demonstrates the critical importance of maintaining up-to-date software and the potential consequences of delayed patch management in enterprise security operations.