CVE-2015-2421 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 6 through 11 allows remote attackers to bypass the ASLR protection mechanism via a crafted web site, aka "Internet Explorer ASLR Bypass."
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 11/29/2024
Microsoft Internet Explorer versions 6 through 11 contained a critical vulnerability that allowed remote attackers to circumvent Address Space Layout Randomization protections through maliciously crafted web content. This vulnerability specifically targeted the memory management mechanisms within the browser's execution environment, enabling adversaries to predict memory layout patterns that should have been randomized for security purposes. The flaw existed in how Internet Explorer handled memory allocation and process isolation, particularly affecting the browser's ability to maintain separate memory spaces for different processes and components. This ASLR bypass vulnerability represented a fundamental weakness in the browser's security architecture that could be exploited to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability involved manipulating the browser's memory management functions to reveal predictable memory addresses that would normally be randomized during normal operation. Attackers could craft specific web pages containing malicious javascript or other executable code that would trigger the flawed memory handling behavior. The vulnerability was particularly dangerous because it affected multiple versions of Internet Explorer simultaneously, making it a widespread concern across enterprise environments. According to CWE standards, this vulnerability maps to CWE-119 Improper Restriction of Operations within a Sphere, as it involved improper handling of memory operations that allowed unauthorized access to memory regions. The flaw essentially allowed attackers to defeat one of the primary defenses against exploitation techniques such as return-oriented programming and stack smashing attacks.
The operational impact of this vulnerability was severe and far-reaching, as it enabled attackers to bypass multiple layers of security protection that were designed to prevent code execution attacks. Organizations running affected versions of Internet Explorer faced significant risk of compromise, as the vulnerability could be exploited through simple web browsing activities without requiring user interaction beyond visiting a malicious website. The attack surface extended beyond individual user machines to entire corporate networks, as a single compromised browser instance could provide attackers with a foothold for further network infiltration. This vulnerability aligned with ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, as it leveraged browser-based scripting capabilities to exploit memory management flaws. Security professionals noted that the vulnerability was particularly concerning because it could be combined with other exploits to create more sophisticated attack chains.
Mitigation strategies for this vulnerability required immediate action from organizations, including applying Microsoft security patches and updates as soon as they became available. System administrators needed to implement browser hardening measures such as disabling unnecessary browser features, implementing enhanced security zones, and deploying additional security software to detect and prevent exploitation attempts. The vulnerability highlighted the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies. Organizations were advised to consider migrating away from Internet Explorer to more modern browsers with better security track records and more robust memory management implementations. Additionally, network monitoring solutions were recommended to detect anomalous behavior that might indicate exploitation attempts, and security awareness training was emphasized to help users recognize potentially malicious web content. The vulnerability underscored the critical need for continuous security monitoring and rapid response capabilities when dealing with memory corruption and exploitation vulnerabilities in widely used software applications.