CVE-2016-7240 in Edge
Summary
by MITRE
The Chakra JavaScript scripting engine in Microsoft Edge allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site, aka "Scripting Engine Memory Corruption Vulnerability," a different vulnerability than CVE-2016-7200, CVE-2016-7201, CVE-2016-7202, CVE-2016-7203, CVE-2016-7208, CVE-2016-7242, and CVE-2016-7243.
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Analysis
by VulDB Data Team • 02/21/2025
The CVE-2016-7240 vulnerability represents a critical memory corruption flaw within Microsoft Edge's Chakra JavaScript engine, exposing users to significant security risks through web-based attacks. This vulnerability specifically affects the scripting engine's handling of JavaScript objects and memory management, creating opportunities for remote code execution or denial of service conditions. The flaw manifests when malicious websites craft specific JavaScript code that triggers improper memory handling within the Chakra engine, leading to unpredictable behavior and potential system compromise. Security researchers identified this issue as distinct from several other related vulnerabilities in the same vulnerability family, emphasizing its unique characteristics while maintaining connections to broader exploitation patterns within the Microsoft Edge browser ecosystem. The vulnerability's classification under CWE-125 indicates improper memory access patterns that allow attackers to manipulate memory contents beyond intended boundaries, while its relationship to the broader ATT&CK framework demonstrates how such flaws can be leveraged for initial access and execution phases of cyber attacks.
The technical implementation of this vulnerability involves the Chakra engine's improper handling of JavaScript object references and memory allocation during script execution. Attackers can craft malicious web pages containing specifically structured JavaScript code that exploits memory corruption patterns within the engine's object model. When Microsoft Edge processes these crafted scripts, the Chakra engine fails to properly validate memory boundaries during object manipulation, leading to memory corruption that can be leveraged to execute arbitrary code with the privileges of the browser process. The vulnerability typically occurs during dynamic object creation and method invocation scenarios where the engine's memory management routines fail to properly handle edge cases in object reference counting or memory reallocation. This type of memory corruption vulnerability represents a classic example of how JavaScript engines can be exploited through carefully crafted input that triggers buffer overflows or use-after-free conditions within the engine's memory management subsystem.
The operational impact of CVE-2016-7240 extends beyond simple denial of service conditions to potentially enable full system compromise when exploited successfully. Organizations running Microsoft Edge browsers face significant risk as attackers can leverage this vulnerability to execute malicious code on targeted systems without requiring user interaction beyond visiting a compromised website. The vulnerability's exploitation potential makes it particularly dangerous in targeted attack scenarios where adversaries seek to establish persistent access or escalate privileges within compromised environments. Security professionals must understand that this vulnerability can be used in conjunction with other exploitation techniques to bypass security controls, particularly when combined with browser sandbox escape mechanisms or privilege escalation vectors. The vulnerability's presence in the Chakra engine means that any web-based attack surface within Microsoft Edge becomes a potential entry point for attackers seeking to compromise Windows systems through browser-based exploitation techniques.
Mitigation strategies for CVE-2016-7240 require immediate patch deployment and comprehensive browser security hardening measures. Microsoft released security updates addressing this vulnerability through regular Windows updates, making patch management a critical defensive measure for organizations. System administrators should prioritize immediate deployment of the relevant security patches while implementing additional browser security controls such as enhanced tracking protection, restricted JavaScript execution, and browser sandboxing configurations. Organizations should also consider implementing network-based protections such as web application firewalls and content filtering solutions to detect and block malicious JavaScript patterns associated with this vulnerability. The implementation of security monitoring solutions capable of detecting anomalous JavaScript execution patterns and memory access violations provides additional defense layers against exploitation attempts. Regular security assessments and vulnerability scanning should include verification of patched systems to ensure complete remediation of this memory corruption vulnerability, while security awareness training should emphasize the risks associated with visiting untrusted websites and the importance of maintaining current browser security updates.