CVE-2018-8543 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-2018-8541, CVE-2018-8542, CVE-2018-8551, CVE-2018-8555, CVE-2018-8556, CVE-2018-8557, CVE-2018-8588.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-8543 represents a critical memory corruption issue within Microsoft Edge's Chakra scripting engine, which serves as the JavaScript engine powering the browser's web content execution. This flaw resides in how the engine manages object allocation and memory handling during script execution, creating a pathway for malicious actors to potentially execute arbitrary code on affected systems. The vulnerability specifically impacts Microsoft Edge versions that utilize the Chakra engine, as well as applications built on ChakraCore, which is Microsoft's open-source version of the engine used in various environments including Node.js and PowerShell.
The technical nature of this vulnerability stems from improper memory management practices within the Chakra engine's object handling mechanisms, which can lead to heap corruption when processing specially crafted JavaScript code. Attackers can exploit this weakness by delivering malicious web content that triggers the vulnerable code path during script execution, potentially causing the browser to corrupt memory structures and subsequently execute attacker-controlled code with the privileges of the current user. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which deals with stack-based buffer overflow conditions, though in this case the corruption occurs in heap memory rather than stack memory. The flaw demonstrates characteristics consistent with memory safety issues that can enable privilege escalation and arbitrary code execution.
The operational impact of CVE-2018-8543 extends beyond simple browser compromise, as successful exploitation can allow attackers to bypass security mitigations such as address space layout randomization and data execution prevention. This vulnerability particularly affects enterprise environments where Microsoft Edge is widely deployed, as attackers can leverage it to gain unauthorized access to sensitive corporate data or establish persistent backdoors through browser-based attacks. The attack surface includes web applications, email clients that render HTML content, and any system where the affected browser components are present. Organizations running older versions of Microsoft Edge or systems using ChakraCore without proper patching are at significant risk, as the vulnerability can be exploited through drive-by downloads or malicious websites that trigger the memory corruption during normal browsing operations.
Mitigation strategies for CVE-2018-8543 should prioritize immediate patching of affected Microsoft Edge installations and ChakraCore implementations through official Microsoft security updates. Organizations should implement network-based protections such as web application firewalls and content filtering solutions to block access to known malicious domains. Browser hardening measures including disabling unnecessary JavaScript features, implementing strict content security policies, and deploying sandboxing mechanisms can provide additional defense layers. Security teams should also consider monitoring for unusual browser behavior and anomalous memory access patterns that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Windows Command Shell and T1071.001 for Application Layer Protocol: Web Protocols, indicating that exploitation often occurs through web-based attack vectors. System administrators should conduct comprehensive vulnerability assessments to identify all systems using affected Chakra-based components and ensure timely deployment of security patches to prevent exploitation.