CVE-2016-3240 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-2016-3241 and CVE-2016-3242.
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Analysis
by VulDB Data Team • 09/01/2022
This vulnerability affects Microsoft Internet Explorer versions 9 through 11 and represents a critical memory corruption flaw that enables remote code execution or denial of service attacks. The vulnerability arises from improper handling of memory operations within the browser's rendering engine, specifically when processing crafted web content. Attackers can exploit this weakness by hosting malicious web pages that trigger memory corruption during normal browsing operations, potentially allowing them to execute arbitrary code with the privileges of the logged-in user. The flaw demonstrates characteristics consistent with heap-based buffer overflow conditions and memory management errors that fall under CWE-121, heap-based buffer overflow, and CWE-125, out-of-bounds read. The vulnerability is particularly dangerous because it operates at the browser level and can be triggered through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a malicious website.
The technical implementation of this vulnerability involves the exploitation of memory corruption patterns within Internet Explorer's JavaScript engine and HTML parser components. When the browser encounters specially crafted HTML or JavaScript code, it fails to properly validate memory allocations and deallocations, leading to corrupted memory structures that can be manipulated by attackers. The memory corruption occurs during the processing of complex web elements such as DOM objects, JavaScript arrays, or memory-intensive operations. This type of vulnerability aligns with ATT&CK technique T1203, Exploitation for Client Execution, and represents a classic example of a remote code execution vulnerability that leverages browser memory management flaws. The attack surface is extensive since any user visiting a compromised website could be affected, making this a high-risk vulnerability for enterprise environments and individual users alike.
The operational impact of this vulnerability extends beyond simple exploitation to include significant security implications for organizations relying on Internet Explorer for business operations. The ability to execute arbitrary code remotely means that attackers can install malware, steal sensitive data, modify system configurations, or establish persistent access to compromised systems. The denial of service aspect can be used to disrupt business operations by causing browser crashes or system instability, potentially leading to productivity losses and service interruptions. Organizations with legacy systems still using Internet Explorer 9 through 11 face particular risk since these versions are no longer receiving security updates from Microsoft, leaving them vulnerable to exploitation by threat actors who may have already developed working exploits for this vulnerability. The memory corruption nature of the flaw also makes it particularly challenging to detect through traditional security monitoring since the corruption may not immediately manifest as obvious system errors.
Mitigation strategies for this vulnerability require immediate action from system administrators and security teams to address the exposed risk. The primary recommendation involves deploying Microsoft's security patches and updates as soon as they become available, though for older Internet Explorer versions that are no longer supported, organizations should consider migrating to modern browser alternatives such as Microsoft Edge or other supported browsers. Network-based mitigations can include implementing web application firewalls, content filtering systems, and browser isolation technologies to prevent access to known malicious websites. Security monitoring should focus on detecting anomalous browser behavior, memory usage patterns, and potential exploitation attempts through network traffic analysis. Organizations should also implement user education programs to raise awareness about phishing attacks and malicious website visits that could trigger this vulnerability. The vulnerability's classification as a remote code execution flaw necessitates comprehensive incident response planning, including system isolation procedures, forensic analysis capabilities, and communication protocols for potential security breaches. Additionally, implementing sandboxing technologies and browser hardening configurations can provide additional layers of protection against exploitation attempts targeting this memory corruption vulnerability.