CVE-2019-1308 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 CVE ID is unique from CVE-2019-1307, CVE-2019-1335, CVE-2019-1366.
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Analysis
by VulDB Data Team • 09/26/2020
The vulnerability described in CVE-2019-1308 represents a critical memory corruption issue within Microsoft Edge's Chakra scripting engine that enables remote code execution. This flaw exists in the manner in which the Chakra engine manages object memory allocation and handling, creating a pathway for attackers to execute arbitrary code on affected systems. The vulnerability specifically targets the scripting engine's memory management mechanisms, which are fundamental to how web browsers process JavaScript and other scripting languages. Chakra serves as Microsoft's high-performance JavaScript engine that powers Edge's web rendering capabilities and is responsible for interpreting and executing client-side scripts.
The technical implementation of this vulnerability stems from improper memory handling within the Chakra engine's object management system. When processing certain script objects, the engine fails to properly validate memory boundaries and object references, leading to potential buffer overflows or memory corruption states. This memory corruption can be exploited by crafting malicious JavaScript code that manipulates object references in ways that cause the engine to write data beyond allocated memory regions. The flaw operates at a low level within the browser's execution environment, making it particularly dangerous as it can bypass traditional security measures and directly affect system memory. According to CWE standards, this vulnerability maps to CWE-125: Out-of-bounds Read and CWE-787: Out-of-bounds Write, which are common categories for memory corruption vulnerabilities in scripting engines.
The operational impact of CVE-2019-1308 is severe and far-reaching across enterprise and individual computing environments. Attackers can leverage this vulnerability through drive-by downloads, malicious websites, or compromised web applications to remotely execute code on targeted systems without user interaction. The exploitability is particularly concerning because it requires no user interaction beyond visiting a malicious website, making it highly effective for mass deployment attacks. Once successfully exploited, the vulnerability provides attackers with the ability to gain full system control, potentially leading to data theft, system compromise, and lateral movement within networks. The vulnerability affects Microsoft Edge browsers running on Windows 10 and Windows Server 2016, with the attack surface extending to any system where Edge is the default browser or where users may encounter malicious content. This vulnerability aligns with ATT&CK technique T1059.007: Command and Scripting Interpreter: JavaScript, as it exploits JavaScript execution capabilities to achieve remote code execution.
Mitigation strategies for CVE-2019-1308 should prioritize immediate patch deployment through Microsoft's regular security updates and Windows Update mechanisms. Organizations must ensure that all Edge browsers are updated to versions containing the necessary security fixes, as Microsoft released patches specifically addressing this vulnerability in their monthly security updates. System administrators should also implement network-based protections including web application firewalls and content filtering solutions that can detect and block malicious JavaScript patterns associated with this vulnerability. Browser hardening measures such as disabling JavaScript for untrusted sites, implementing strict content security policies, and using sandboxing techniques can provide additional layers of protection. Security monitoring should focus on detecting anomalous JavaScript execution patterns and memory access violations that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of maintaining up-to-date browser security patches and implementing defense-in-depth strategies to protect against sophisticated memory corruption attacks that target core browser components.