CVE-2016-1855 in Safari
Summary
by MITRE
WebKit, as used in Apple iOS before 9.3.2, Safari before 9.1.1, and tvOS before 9.2.1, allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, a different vulnerability than CVE-2016-1854, CVE-2016-1856, and CVE-2016-1857.
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Analysis
by VulDB Data Team • 08/21/2022
This vulnerability exists within WebKit, the web browser engine that powers Apple's Safari browser and iOS web applications. The flaw represents a critical memory corruption issue that can be exploited remotely through malicious web content, making it particularly dangerous for users who browse the internet regularly. The vulnerability affects multiple Apple platforms including iOS versions prior to 9.3.2, Safari versions before 9.1.1, and tvOS versions before 9.2.1, indicating a widespread impact across Apple's ecosystem. This memory corruption vulnerability allows attackers to execute arbitrary code on affected systems or cause denial of service conditions, representing a significant security risk that could lead to complete system compromise.
The technical nature of this vulnerability involves improper memory management within WebKit's rendering engine, specifically when processing crafted web content. Attackers can construct malicious websites that trigger memory corruption during normal web page rendering operations, potentially leading to code execution with the privileges of the web browser process. The flaw is classified as a memory corruption vulnerability under the CWE taxonomy, specifically falling under CWE-119 which deals with improper restriction of operations within a memory buffer. This type of vulnerability typically arises from insufficient bounds checking or improper memory allocation/deallocation procedures that allow attackers to manipulate memory contents beyond intended boundaries.
The operational impact of this vulnerability extends beyond simple code execution to potentially enable full system compromise when combined with other attack vectors. An attacker who successfully exploits this vulnerability could gain unauthorized access to user data, install malicious software, or disrupt normal system operations through denial of service conditions. The remote exploitation capability means users do not need to take any special actions beyond visiting a malicious website, making it particularly dangerous for widespread deployment. This vulnerability aligns with ATT&CK technique T1059 which covers command and script injection, as successful exploitation could enable attackers to execute arbitrary commands on compromised systems through the browser's execution environment.
Mitigation strategies should focus on immediate patching of affected systems to address the underlying memory corruption issue. Apple released security updates for iOS 9.3.2, Safari 9.1.1, and tvOS 9.2.1 that resolve this vulnerability through improved memory management and bounds checking mechanisms. Organizations should implement network-based protections such as web application firewalls and content filtering systems to block access to known malicious domains. Browser security enhancements including sandboxing features and strict content security policies can help reduce the potential impact of successful exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify systems that may still be running affected versions, with priority given to patching high-risk environments such as corporate networks and user workstations that handle sensitive information.