CVE-2016-3241 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 9 through 11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Internet Explorer Memory Corruption Vulnerability," a different vulnerability than CVE-2016-3240 and CVE-2016-3242.
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Analysis
by VulDB Data Team • 09/01/2022
Microsoft Internet Explorer versions 9 through 11 contain a critical memory corruption vulnerability that enables remote attackers to execute arbitrary code or cause denial of service conditions when users visit malicious websites. This vulnerability specifically affects the browser's handling of memory management during web page rendering and script execution processes. The flaw arises from improper validation of memory allocations and deallocations within the browser's JavaScript engine and rendering components, creating opportunities for attackers to manipulate memory structures through carefully crafted web content. The vulnerability is classified under CWE-125 as out-of-bounds read conditions and CWE-787 as out-of-bounds write operations, representing fundamental memory safety issues that can be exploited to gain unauthorized system access or disrupt normal browser operations. Attackers can leverage this vulnerability by hosting malicious web pages that trigger specific memory corruption patterns when the affected browsers attempt to parse and render the content. The exploitation typically involves crafting HTML elements, JavaScript code, or ActiveX controls that cause memory corruption during browser processing, potentially leading to remote code execution with the privileges of the logged-in user. This vulnerability impacts the core browser functionality and represents a significant security risk for organizations relying on older Internet Explorer versions, as it can be exploited through drive-by downloads or malicious web campaigns without requiring user interaction beyond visiting compromised websites. The issue is particularly concerning because it affects multiple versions of Internet Explorer simultaneously, making it a broad attack surface that requires comprehensive remediation across affected systems.
The technical exploitation of this vulnerability demonstrates how memory corruption flaws in web browsers can be leveraged for sophisticated attacks. Attackers typically craft web pages that contain malicious JavaScript or HTML elements designed to trigger specific memory allocation patterns that result in buffer overflows or heap corruption. The vulnerability operates at a low level within the browser's memory management system, where improper bounds checking allows attackers to overwrite memory locations that control program execution flow. This type of exploitation aligns with ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries use vulnerabilities to execute malicious code in the context of the victim's browser. The memory corruption occurs during normal browsing operations, making it particularly dangerous as users may not realize they have been compromised until malicious code has executed. The vulnerability can be chained with other exploits to create more sophisticated attack vectors, and its exploitation can result in complete system compromise depending on the user's privileges and the browser's execution context. Security researchers have identified that this vulnerability can be effectively exploited in the wild through various attack vectors including compromised websites, phishing campaigns, and social engineering tactics that direct users to malicious content.
Organizations affected by this vulnerability face significant operational risks including potential data breaches, system compromise, and denial of service incidents that can impact business continuity. The vulnerability's ability to cause memory corruption means that even successful exploitation attempts may result in system instability or crashes, creating denial of service conditions that can be used as part of broader attack campaigns. The impact extends beyond individual user systems to enterprise networks where multiple users may be simultaneously exposed to the same malicious content. Security teams must prioritize immediate remediation through Microsoft security updates and patches, as the vulnerability has been actively exploited in the wild. Organizations should implement network-based protections including web application firewalls and content filtering solutions that can detect and block malicious web content targeting this vulnerability. Browser hardening measures including disabling unnecessary browser features, implementing strict content security policies, and using security-enhanced browser configurations can provide additional layers of protection. The vulnerability also highlights the importance of maintaining up-to-date browser software and implementing comprehensive vulnerability management programs that include regular security assessments and penetration testing to identify similar memory corruption issues. Organizations should also consider implementing user education programs to reduce the risk of social engineering attacks that could lead users to visit malicious websites hosting exploit code.
Mitigation strategies for this vulnerability should include immediate deployment of Microsoft security patches and updates, as well as implementation of network-level protections to prevent access to known malicious domains. Organizations should consider implementing browser isolation technologies and sandboxing solutions to limit the impact of successful exploitation attempts. Security monitoring should include detection of unusual browser behavior, memory access patterns, and network traffic that may indicate exploitation attempts. The vulnerability underscores the critical need for organizations to maintain current security patches and to implement defense-in-depth strategies that include multiple layers of protection. Regular security assessments should be conducted to identify similar memory corruption vulnerabilities in other software components and to validate the effectiveness of implemented mitigations. Additionally, organizations should establish incident response procedures specifically designed to handle browser-based exploitation attempts, including forensic analysis capabilities to investigate successful attacks and prevent future occurrences. The vulnerability serves as a reminder of the ongoing risks associated with legacy browser software and the importance of migrating to supported platforms that receive regular security updates and patches.