CVE-2016-1783 in iOS
Summary
by MITRE
WebKit in Apple iOS before 9.3, Safari before 9.1, and tvOS before 9.2 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.
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Analysis
by VulDB Data Team • 07/11/2022
The vulnerability identified as CVE-2016-1783 represents a critical memory corruption flaw within WebKit, the rendering engine that powers Apple's Safari browser and iOS web applications. This vulnerability affects multiple Apple platforms including iOS versions prior to 9.3, Safari versions before 9.1, and tvOS versions before 9.2, creating a widespread attack surface that could be exploited by remote threat actors. The flaw resides in how WebKit processes certain web content, specifically when handling crafted web sites that contain maliciously constructed data structures or memory allocations that lead to unpredictable behavior.
The technical nature of this vulnerability stems from improper memory management and bounds checking within WebKit's JavaScript engine and rendering components. When a user visits a maliciously crafted web page, the vulnerable code path triggers memory corruption that can result in arbitrary code execution or system crashes. This type of vulnerability typically occurs when the browser fails to properly validate input data or when memory allocation routines do not adequately protect against buffer overflows or use-after-free conditions. The flaw can be exploited through various attack vectors including malicious web pages, phishing sites, or compromised websites that serve the malicious content to unsuspecting users.
From an operational perspective, this vulnerability poses significant risks to enterprise and individual users alike, as it enables remote code execution without requiring any user interaction beyond visiting a malicious website. The impact extends beyond simple denial of service to potentially allow full system compromise, data theft, or persistent backdoor installation. Attackers could leverage this vulnerability to gain unauthorized access to devices, execute malicious payloads, or establish persistent access to compromised systems. The vulnerability's remote exploitability makes it particularly dangerous as it can be triggered through standard web browsing activities without requiring physical access or additional user actions.
Organizations should prioritize immediate patching of affected systems to remediate this vulnerability, as the attack surface is broad and the potential impact is severe. The remediation process should include updating iOS to version 9.3 or later, Safari to version 9.1 or later, and tvOS to version 9.2 or later. Security teams should also implement network-based protections such as web application firewalls and content filtering solutions to help detect and block malicious web content. Additionally, user education programs should emphasize the importance of avoiding suspicious websites and keeping software up to date. This vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and may also relate to CWE-787, representing out-of-bounds write conditions, while potentially mapping to ATT&CK technique T1203 for legitimate program execution through web-based attacks. The vulnerability demonstrates the critical importance of maintaining up-to-date software and implementing layered security controls to protect against sophisticated remote exploitation techniques.