CVE-2018-8631 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists when Internet Explorer improperly accesses objects in memory, aka "Internet Explorer Memory Corruption Vulnerability." This affects Internet Explorer 9, Internet Explorer 11, Internet Explorer 10.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability identified as CVE-2018-8631 represents a critical memory corruption flaw within Microsoft Internet Explorer browsers affecting versions 9, 10, and 11. This vulnerability stems from improper handling of object references in memory during web page rendering processes, creating opportunities for malicious actors to execute arbitrary code on affected systems. The flaw manifests when Internet Explorer encounters specially crafted web content that triggers memory corruption during object manipulation, potentially allowing attackers to gain unauthorized system access and execute malicious payloads. The vulnerability is classified under CWE-125 as an out-of-bounds read condition that can lead to memory corruption, making it particularly dangerous for enterprise environments where legacy browser support remains necessary. According to the ATT&CK framework, this vulnerability maps to T1203 - Exploitation for Client Execution, representing a common attack pattern where adversaries leverage browser vulnerabilities to establish persistent access to target systems.
The technical exploitation of CVE-2018-8631 occurs through the manipulation of JavaScript objects within Internet Explorer's memory space, specifically targeting the way the browser handles object references during dynamic content rendering. When a user visits a malicious website or opens a specially crafted document, the vulnerable browser processes malformed JavaScript code that causes memory corruption, leading to potential code execution. Attackers can leverage this vulnerability to deploy malware, establish backdoors, or escalate privileges within the compromised system. The memory corruption aspect of this vulnerability creates a pathway for attackers to bypass modern security mechanisms such as address space layout randomization and data execution prevention, as the flaw allows for predictable memory manipulation. This type of vulnerability is particularly concerning in enterprise environments where older browser versions are still in use for legacy application compatibility, as these systems often lack the security updates and patches that would mitigate such memory corruption issues.
The operational impact of CVE-2018-8631 extends beyond simple remote code execution to encompass significant enterprise security risks including data breaches, system compromise, and potential lateral movement within networks. Organizations running affected Internet Explorer versions face increased risk of targeted attacks, particularly those that leverage spear-phishing campaigns or drive-by downloads to exploit this vulnerability. The vulnerability's exploitation typically requires user interaction through visiting malicious websites or opening compromised documents, making social engineering components integral to successful attacks. Security teams must consider the broader implications of this vulnerability on their overall security posture, as it represents a known weakness that can be exploited by threat actors without requiring advanced technical skills or significant resources. The vulnerability's persistence across multiple Internet Explorer versions indicates a fundamental flaw in the browser's memory management that requires immediate remediation through patching or browser replacement strategies.
Mitigation strategies for CVE-2018-8631 should prioritize immediate patch deployment through Microsoft's security updates, as the vulnerability has been addressed through official security releases. Organizations should implement browser hardening measures including disabling unnecessary browser features, implementing strict content filtering, and deploying enhanced security configurations such as Internet Explorer's Enhanced Security Configuration. Network-level protections including web application firewalls and intrusion detection systems can help detect and prevent exploitation attempts targeting this vulnerability. Security teams should also consider implementing browser isolation techniques or transitioning to modern browser alternatives that receive regular security updates and support. The vulnerability's classification as a memory corruption issue makes it particularly susceptible to exploitation through techniques such as heap spraying or return-oriented programming, emphasizing the need for comprehensive memory protection mechanisms. Regular security assessments and vulnerability scanning should be conducted to ensure all affected systems are properly patched and that legacy browser usage is minimized through proper application compatibility planning and migration strategies.