CVE-2018-8629 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-2018-8583, CVE-2018-8617, CVE-2018-8618, CVE-2018-8624.
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Analysis
by VulDB Data Team • 06/18/2023
The vulnerability described in CVE-2018-8629 represents a critical memory corruption issue within Microsoft Edge's Chakra scripting engine, which serves as the JavaScript engine powering the browser's execution environment. This flaw enables remote code execution when malicious actors craft specific JavaScript code that exploits improper memory handling during object manipulation. The vulnerability specifically manifests when the Chakra engine processes certain object operations in memory, leading to unpredictable behavior that can be leveraged for arbitrary code execution. The Chakra engine is integral to Edge's functionality as it interprets and executes JavaScript code from web pages, making this vulnerability particularly dangerous for web-based attacks.
The technical nature of this vulnerability stems from insufficient bounds checking and memory management within the Chakra scripting engine's object handling mechanisms. When legitimate JavaScript code triggers specific memory operations involving objects, the engine fails to properly validate memory access patterns, resulting in memory corruption that can be exploited to overwrite critical memory locations. This type of vulnerability falls under the CWE-121 category of "Stack-based Buffer Overflow" and aligns with ATT&CK technique T1059.007 for Scripting, where adversaries leverage browser-based scripting engines to execute malicious code. The memory corruption occurs during the object lifecycle management within Chakra's memory allocator, where objects may be improperly freed or reallocated without proper validation.
The operational impact of CVE-2018-8629 is severe and far-reaching, as it allows attackers to execute arbitrary code on vulnerable systems without requiring user interaction beyond visiting a malicious website. This makes it particularly dangerous for phishing campaigns and drive-by download attacks where users simply need to browse to compromised sites. The vulnerability affects not only Microsoft Edge but also ChakraCore, which is used in various Microsoft products and applications, extending the attack surface significantly. Attackers can leverage this vulnerability to install malware, steal user credentials, or establish persistent backdoors on affected systems, making it a preferred target for advanced persistent threat groups. The remote exploitation capability means that attackers can compromise systems from anywhere on the internet without needing physical access or local privileges.
Mitigation strategies for CVE-2018-8629 should prioritize immediate patch deployment through Microsoft's security updates, as the vulnerability was addressed in the August 2018 security releases. Organizations should implement network-based protections such as web application firewalls and content filtering systems to block known malicious JavaScript patterns. Browser hardening measures including disabling unnecessary scripting features, implementing strict content security policies, and using sandboxing technologies can provide additional defense layers. Security teams should also consider implementing monitoring for suspicious JavaScript behavior and memory access patterns that could indicate exploitation attempts. The vulnerability's classification under the Common Vulnerabilities and Exposures database and its mapping to ATT&CK framework techniques emphasize the need for comprehensive security operations that include both preventive measures and incident response readiness. Regular security assessments and penetration testing should verify that systems are properly patched and configured to prevent exploitation of this memory corruption vulnerability.