CVE-2018-8133 in Edge
Summary
by MITRE
A remote code execution vulnerability exists in the way that the Chakra scripting engine handles objects in memory in Microsoft Edge, aka "Chakra Scripting Engine Memory Corruption Vulnerability." This affects Microsoft Edge, ChakraCore. This CVE ID is unique from CVE-2018-0943, CVE-2018-8130, CVE-2018-8145, CVE-2018-8177.
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Analysis
by VulDB Data Team • 09/05/2025
The vulnerability identified as CVE-2018-8133 represents a critical memory corruption issue within Microsoft Edge's Chakra scripting engine, which serves as the JavaScript engine powering the browser's execution environment. This flaw specifically manifests when the engine processes objects in memory, creating conditions that could be exploited by malicious actors to execute arbitrary code remotely. The vulnerability affects not only Microsoft Edge but also ChakraCore, the standalone version of the Chakra engine used in various applications and environments beyond the browser. The Chakra engine's handling of memory objects becomes compromised during normal script execution, creating potential attack vectors that adversaries can leverage to gain unauthorized system access. This issue is distinct from several other related vulnerabilities including CVE-2018-0943, CVE-2018-8130, CVE-2018-8145, and CVE-2018-8177, each representing different aspects of the Chakra engine's security weaknesses. The vulnerability operates at a fundamental level within the browser's JavaScript execution framework, where improper memory management creates opportunities for attackers to manipulate object references and execute malicious payloads.
The technical nature of this vulnerability stems from improper memory handling within the Chakra scripting engine's object management system. When JavaScript objects are created, manipulated, or destroyed within the browser environment, the engine's memory allocation and deallocation processes may fail to properly validate object states or maintain memory boundaries. This memory corruption occurs during normal script execution scenarios, particularly when dealing with complex object interactions and memory reuse patterns. The flaw allows attackers to craft malicious JavaScript code that exploits these memory handling deficiencies, potentially leading to heap corruption or other memory-related issues that can be leveraged for code execution. The vulnerability's impact is amplified by the fact that it operates within the browser's trusted execution environment, where legitimate scripts have full access to system resources and can interact with various browser components. According to CWE classification, this vulnerability maps to CWE-125: Out-of-bounds Read and CWE-787: Out-of-bounds Write, reflecting the memory corruption patterns that enable remote code execution.
The operational impact of CVE-2018-8133 extends beyond simple browser compromise, as successful exploitation can lead to complete system takeover through various attack vectors. An attacker could deliver malicious content through phishing emails, compromised websites, or drive-by downloads that trigger the vulnerable code path when users browse to malicious sites. The remote code execution capability allows adversaries to install malware, steal sensitive data, establish persistence mechanisms, or use the compromised system as a launch point for further attacks. This vulnerability particularly affects enterprise environments where users may browse untrusted websites or receive malicious emails, creating multiple attack surfaces. The Chakra engine's integration with Microsoft Edge means that any successful exploitation directly compromises the browser's security model, potentially bypassing various security mitigations such as sandboxing and memory protection mechanisms. Organizations using ChakraCore in standalone applications face similar risks, as the same memory corruption vulnerabilities exist in the engine's core functionality.
Mitigation strategies for CVE-2018-8133 primarily focus on immediate patch deployment and security configuration hardening. Microsoft released security updates that address the memory corruption issues within the Chakra engine, requiring users to install the latest cumulative updates for Microsoft Edge and Windows operating systems. Organizations should implement proactive security measures including browser hardening configurations, content filtering, and network-based protections to reduce the attack surface. The implementation of exploit protection mechanisms such as Address Space Layout Randomization (ASLR), Data Execution Prevention (DEP), and Control Flow Guard (CFG) can help mitigate exploitation attempts. Security teams should also consider implementing web application firewalls and monitoring for suspicious JavaScript execution patterns that may indicate exploitation attempts. According to ATT&CK framework, this vulnerability aligns with T1059.007: Command and Scripting Interpreter: JavaScript and T1203: Exploitation for Client Execution, reflecting the attack patterns commonly used by adversaries. Regular security assessments and vulnerability scanning should be conducted to identify systems running vulnerable versions of the Chakra engine, while incident response procedures should be updated to address potential exploitation of this memory corruption flaw.