CVE-2018-8291 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in the way the scripting engine handles objects in memory in Microsoft browsers, aka "Scripting Engine Memory Corruption Vulnerability." This affects ChakraCore, Internet Explorer 11, Microsoft Edge. This CVE ID is unique from CVE-2018-8242, CVE-2018-8283, CVE-2018-8287, CVE-2018-8288, CVE-2018-8296, CVE-2018-8298.
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Analysis
by VulDB Data Team • 09/08/2025
The vulnerability described in CVE-2018-8291 represents a critical memory corruption issue within Microsoft's scripting engine that affects multiple browser platforms including Internet Explorer 11 and Microsoft Edge. This flaw resides in the ChakraCore JavaScript engine implementation and demonstrates how improper memory handling can lead to remote code execution. The vulnerability specifically targets the way the scripting engine manages objects in memory, creating opportunities for attackers to exploit memory corruption patterns that could result in arbitrary code execution on affected systems. Such issues are particularly dangerous because they can be triggered through web-based attacks without requiring user interaction beyond visiting a malicious website.
The technical nature of this vulnerability stems from improper memory management within the scripting engine's object handling mechanisms. When the ChakraCore engine processes certain JavaScript objects in memory, it fails to properly validate or manage memory allocation and deallocation processes. This memory corruption occurs during the execution of malicious JavaScript code that is designed to manipulate object references and memory addresses in ways that cause the engine to behave unpredictably. The flaw allows attackers to craft specific JavaScript payloads that can overwrite memory locations or execute code at privileged memory addresses, effectively bypassing standard security protections. This type of vulnerability is classified as a memory corruption vulnerability under CWE-122 and represents a classic buffer overflow or memory management issue that can be exploited through carefully crafted inputs.
The operational impact of CVE-2018-8291 extends across multiple Microsoft browser platforms and affects users who may encounter malicious web content through various attack vectors. The vulnerability can be exploited through drive-by downloads, malicious websites, or compromised web applications that serve JavaScript code designed to trigger the memory corruption. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the affected browser process, potentially leading to full system compromise. The remote code execution capability means that attackers can gain persistent access to systems without requiring physical presence or user interaction beyond visiting a malicious website. This vulnerability particularly affects enterprise environments where users may inadvertently visit compromised websites or receive malicious email attachments that contain embedded exploit code.
Mitigation strategies for CVE-2018-8291 should focus on immediate patching and browser hardening measures. Microsoft released security updates that address this vulnerability through patches to Internet Explorer and Microsoft Edge browsers, which should be deployed immediately across all affected systems. Organizations should implement network-based protections such as web application firewalls and content filtering systems to block access to known malicious domains. Browser hardening techniques including disabling JavaScript for untrusted sites, implementing strict security policies, and using sandboxing mechanisms can provide additional layers of protection. The vulnerability aligns with ATT&CK technique T1059.007 for Windows Command Shell and T1203 for Exploitation for Client Execution, indicating that attackers may use this vulnerability as part of broader attack chains. Security teams should monitor for indicators of compromise including unusual network traffic patterns, suspicious JavaScript execution, and unauthorized system access attempts that may signal exploitation attempts. Regular security assessments and vulnerability scanning should include checks for unpatched systems running affected browser versions to ensure comprehensive protection against this and similar memory corruption vulnerabilities.