CVE-2017-0235 in Edge
Summary
by MITRE
A remote code execution vulnerability exists in Microsoft Edge in the way that the Chakra JavaScript engine renders when handling 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-2017-0236, and CVE-2017-0238.
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Analysis
by VulDB Data Team • 12/22/2020
The vulnerability identified as CVE-2017-0235 represents a critical remote code execution flaw within Microsoft Edge's Chakra JavaScript engine, specifically manifesting as a scripting engine memory corruption vulnerability. This issue arises during the rendering process when Edge handles objects in memory, creating an exploitable condition that adversaries can leverage to execute arbitrary code on affected systems. The vulnerability's classification as a memory corruption flaw indicates that improper memory management during JavaScript object handling allows attackers to manipulate memory layout and potentially overwrite critical system resources. The Chakra engine's failure to properly validate or sanitize object memory operations creates a pathway for malicious JavaScript code to corrupt memory structures and gain unauthorized system access.
The technical exploitation of this vulnerability occurs through carefully crafted JavaScript code that triggers memory corruption within the Chakra engine's memory management subsystem. When Edge processes malicious JavaScript objects, the engine's memory handling mechanisms fail to properly validate object boundaries or memory allocation patterns, leading to buffer overflows or memory corruption that can be leveraged by attackers. This type of vulnerability typically involves manipulating object references, memory pointers, or object layout in ways that cause the JavaScript engine to write data beyond allocated memory regions. The flaw demonstrates poor input validation and memory safety practices within the engine's object handling routines, creating opportunities for attackers to inject malicious code into the execution flow. According to CWE classification, this vulnerability maps to CWE-125: Out-of-bounds Read and CWE-787: Out-of-bounds Write, both of which are fundamental memory safety issues that enable remote code execution.
The operational impact of CVE-2017-0235 is severe and far-reaching within enterprise and individual computing environments. Successful exploitation allows remote attackers to execute arbitrary code with the privileges of the Edge browser process, potentially leading to complete system compromise. Attackers can leverage this vulnerability through various attack vectors including malicious websites, phishing emails with embedded JavaScript, or compromised web services that deliver exploit code. The vulnerability's remote nature means that users need not interact directly with malicious content for exploitation to occur, making it particularly dangerous in targeted attacks. Organizations face significant risk as this vulnerability can be exploited in the wild without user interaction, potentially enabling advanced persistent threats or lateral movement within networks. The vulnerability's presence in Microsoft Edge makes it particularly concerning for organizations that rely on Windows-based systems for web browsing, as it affects the browser's core JavaScript processing capabilities.
Mitigation strategies for CVE-2017-0235 should focus on immediate patch deployment and operational security measures. Microsoft released security updates that address the memory corruption issues within the Chakra engine, and organizations must prioritize applying these patches to all affected systems. In addition to patching, network-level defenses including web application firewalls and content filtering systems can help detect and block malicious JavaScript payloads. Browser hardening techniques such as disabling JavaScript for untrusted websites, implementing strict content security policies, and using sandboxing mechanisms can reduce the attack surface. Security monitoring should include detection of suspicious JavaScript behavior patterns and anomalous memory access patterns that may indicate exploitation attempts. According to ATT&CK framework, this vulnerability maps to T1059.007: Command and Scripting Interpreter: JavaScript, and T1203: Exploitation for Client Execution, highlighting the attack techniques that leverage such memory corruption flaws. Organizations should also consider implementing automated vulnerability scanning and penetration testing to identify potential exploitation opportunities and ensure proper patch management across all systems. The vulnerability underscores the importance of maintaining up-to-date security patches and implementing layered security approaches to protect against sophisticated browser-based attacks.