CVE-2017-8646 in Edge
Summary
by MITRE
Microsoft Edge in Windows 10 1511, 1607, 1703, and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user due to the way that Microsoft browser JavaScript engines render content when handling objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2017-8634, CVE-2017-8635, CVE-2017-8636, CVE-2017-8638, CVE-2017-8639, CVE-2017-8640, CVE-2017-8641, CVE-2017-8645, CVE-2017-8647, CVE-2017-8655, CVE-2017-8656, CVE-2017-8657, CVE-2017-8670, CVE-2017-8671, CVE-2017-8672, and CVE-2017-8674.
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Analysis
by VulDB Data Team • 12/14/2025
This vulnerability represents a critical memory corruption flaw within Microsoft Edge's JavaScript engine that affects multiple Windows 10 versions including 1511, 1607, and 1703, as well as Windows Server 2016. The issue stems from improper handling of objects in memory during JavaScript execution, creating a pathway for remote code execution attacks. The vulnerability specifically targets the scripting engine's memory management functions, where malformed or maliciously crafted JavaScript code can trigger buffer overflows or use-after-free conditions that allow attackers to overwrite critical memory locations. This type of vulnerability falls under the CWE-125 vulnerability category, which describes out-of-bounds read conditions, and is classified as a memory corruption issue that enables arbitrary code execution. The flaw exists in the V8 JavaScript engine implementation within Microsoft Edge, making it particularly dangerous as it leverages the browser's legitimate JavaScript processing capabilities to execute malicious payloads.
The operational impact of this vulnerability is severe as it allows attackers to execute arbitrary code with the privileges of the currently logged-in user without requiring any additional privileges or user interaction. This means that a successful exploitation could lead to complete system compromise, data theft, or deployment of additional malware. Attackers typically exploit this vulnerability through crafted web pages delivered via phishing emails, malicious websites, or compromised advertising networks. The vulnerability is particularly concerning because it affects the browser's core JavaScript engine, which is actively used in daily browsing activities, making it a prime target for widespread exploitation. The attack surface is extensive as any user visiting a malicious website could be compromised, with no user interaction required beyond simply loading the compromised page in Microsoft Edge. This aligns with ATT&CK technique T1203, which covers exploitation for execution through browser-based attacks.
Mitigation strategies for this vulnerability require immediate patching of affected systems, as Microsoft released security updates to address the memory corruption issues in their JavaScript engines. Organizations should prioritize deployment of the relevant security updates, particularly KB4019990 for Windows 10 versions 1511, 1607, and 1703, along with the corresponding update for Windows Server 2016. Additionally, implementing browser hardening measures such as enabling enhanced security features, restricting JavaScript execution in untrusted contexts, and deploying application whitelisting policies can provide additional defense layers. Network-based protections including web application firewalls and content filtering systems can help detect and block malicious JavaScript payloads before they reach vulnerable systems. Security monitoring should focus on unusual JavaScript execution patterns and memory access violations that might indicate exploitation attempts. The vulnerability demonstrates the importance of keeping browser components updated and highlights the need for regular security assessments of web-based attack surfaces, particularly in enterprise environments where multiple users may be exposed to malicious web content through various attack vectors.