CVE-2015-1685 in Internet Explorer
Summary
by MITRE
Microsoft Internet Explorer 11 allows remote attackers to bypass the ASLR protection mechanism via a crafted web site, aka "Internet Explorer ASLR Bypass."
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Analysis
by VulDB Data Team • 05/11/2022
Microsoft Internet Explorer 11 contains a critical vulnerability that undermines the operating system's address space layout randomization protection mechanism, creating a significant security risk for users. This vulnerability specifically affects the browser's implementation of ASLR, which is a fundamental exploit mitigation technique designed to prevent attackers from reliably predicting memory addresses during exploitation attempts. The flaw enables remote attackers to bypass this crucial security feature through carefully crafted web content, fundamentally weakening the system's defenses against various exploit techniques.
The technical nature of this vulnerability stems from how Internet Explorer 11 handles memory layout and address space management when processing web content. ASLR works by randomizing the memory locations where critical system components and libraries are loaded, making it extremely difficult for attackers to execute successful buffer overflow or code injection attacks. However, this vulnerability in IE11 allows malicious actors to predict or determine the memory addresses where specific components are loaded, effectively neutralizing the protection. The flaw likely exists in how the browser's memory management subsystem interacts with the operating system's ASLR implementation, potentially through improper handling of memory allocation or through predictable address patterns in the browser's own memory layout.
The operational impact of this vulnerability is severe and far-reaching, as it provides attackers with a pathway to bypass one of the most important exploit mitigations in modern operating systems. When ASLR is successfully bypassed, attackers can more easily execute buffer overflow attacks, use return-oriented programming techniques, or perform other memory corruption exploits that would otherwise be significantly more difficult or impossible to carry out. This vulnerability affects all users of Internet Explorer 11 who visit malicious websites, creating a widespread attack surface that can be exploited through web-based delivery mechanisms. The risk is particularly concerning because IE11 was widely deployed across enterprise environments and personal computers, amplifying the potential impact of successful exploitation attempts.
Organizations and users should implement immediate mitigations to address this vulnerability, including applying the relevant Microsoft security updates as soon as they become available. The recommended approach involves keeping Internet Explorer updated with the latest security patches, which typically include fixes for memory management and address space layout issues. Additionally, implementing browser hardening techniques such as enabling enhanced protection modes, using security features like DEP and ASLR at the system level, and employing network-level protections can help reduce the risk of exploitation. From a defensive perspective, this vulnerability aligns with the ATT&CK technique T1059.001 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as attackers can leverage the bypassed ASLR to execute more sophisticated attacks. Organizations should also consider implementing web application firewalls, monitoring for suspicious browser behavior, and maintaining up-to-date threat intelligence to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of maintaining current security patches and implementing defense-in-depth strategies to protect against sophisticated exploit techniques that target fundamental system protections. This issue represents a classic example of how browser vulnerabilities can undermine operating system security mechanisms, highlighting the need for comprehensive security approaches that address both application-level and system-level protections.
CWE-119 represents the underlying weakness in this vulnerability, which involves the improper handling of memory access and address space management. The ATT&CK framework categorizes this as a privilege escalation technique through exploitation of memory corruption vulnerabilities, specifically targeting the bypass of operating system security mitigations. This vulnerability underscores the importance of maintaining robust security practices across all layers of the computing environment, as a single browser vulnerability can compromise the effectiveness of system-wide security protections. The widespread deployment of Internet Explorer 11 made this vulnerability particularly dangerous, as it could potentially affect large numbers of users and systems simultaneously. Security teams should prioritize this vulnerability in their risk assessment and remediation planning, ensuring that all affected systems receive immediate patching and that appropriate monitoring is implemented to detect potential exploitation attempts.