CVE-2017-0238 in Internet Explorer
Summary
by MITRE
A remote code execution vulnerability exists in Microsoft browsers in the way JavaScript scripting engines handle objects in memory, aka "Scripting Engine Memory Corruption Vulnerability." This CVE ID is unique from CVE-2017-0224, CVE-2017-0228, CVE-2017-0229, CVE-2017-0230, CVE-2017-0234, CVE-2017-0235, and CVE-2017-0236.
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Analysis
by VulDB Data Team • 12/23/2020
The vulnerability identified as CVE-2017-0238 represents a critical memory corruption flaw within Microsoft's JavaScript scripting engines that affects multiple browser implementations including Internet Explorer and Microsoft Edge. This vulnerability specifically targets the way these browsers handle object management in memory, creating a pathway for remote code execution attacks that can be exploited by malicious actors without user interaction. The flaw resides in the underlying scripting engine components that process JavaScript code, making it particularly dangerous as it can be triggered through standard web browsing activities. Security researchers have classified this issue as a remote code execution vulnerability due to its ability to allow attackers to execute arbitrary code on affected systems, potentially leading to complete system compromise.
The technical nature of this vulnerability stems from improper memory handling within the JavaScript engine's object allocation and deallocation processes. When browsers process certain JavaScript constructs, particularly those involving object manipulation and memory management, the scripting engine fails to properly validate memory boundaries or object references. This memory corruption occurs during the execution of malicious JavaScript code that is designed to exploit specific patterns in how objects are stored and accessed in memory. The vulnerability manifests when the engine attempts to manage object lifecycles, particularly in scenarios involving object reuse, garbage collection, or complex object hierarchies. This flaw aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write operations that can lead to memory corruption.
The operational impact of CVE-2017-0238 extends far beyond simple browser exploitation, as it provides attackers with a powerful vector for achieving persistent system compromise. Once successfully exploited, this vulnerability enables attackers to execute arbitrary code with the privileges of the affected browser process, which typically runs with user-level permissions but can potentially be escalated to higher privileges. The vulnerability affects a broad range of Microsoft products including Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Server 2008, Windows Server 2012, Windows Server 2016, and various versions of Microsoft Edge and Internet Explorer. Attackers can leverage this vulnerability through malicious websites, email attachments, or compromised web services, making it particularly dangerous in enterprise environments where users frequently browse the internet. The vulnerability's classification under the ATT&CK framework places it within the T1059.007 technique category, which involves the use of scripting languages for execution, and T1203, which covers exploitation for privilege escalation.
Mitigation strategies for CVE-2017-0238 focus primarily on applying Microsoft's security patches and updates as quickly as possible, as the vulnerability has been addressed through the Microsoft Security Response Center's patch releases. Organizations should prioritize immediate deployment of the relevant security updates, particularly those released in the January 2017 Microsoft Security Bulletins, which specifically addressed this scripting engine memory corruption issue. Additional protective measures include implementing enhanced browser security configurations, disabling unnecessary JavaScript functionality, and deploying web application firewalls or intrusion prevention systems to monitor for suspicious JavaScript patterns. Security administrators should also consider implementing browser isolation techniques and maintaining strict network segmentation to limit the potential impact of successful exploitation attempts. The vulnerability demonstrates the critical importance of keeping browser implementations up to date, as it represents a fundamental flaw in how scripting engines manage memory that could be exploited by attackers with minimal user interaction requirements.