CVE-2018-0858 in ChakraCore
Summary
by MITRE
ChakraCore allows remote code execution, due to how the ChakraCore scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2018-0834, CVE-2018-0835, CVE-2018-0836, CVE-2018-0837, CVE-2018-0838, CVE-2018-0840, CVE-2018-0856, CVE-2018-0857, CVE-2018-0859, CVE-2018-0860, CVE-2018-0861, and CVE-2018-0866.
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Analysis
by VulDB Data Team • 02/03/2021
The vulnerability identified as CVE-2018-0858 represents a critical memory corruption flaw within Microsoft ChakraCore JavaScript engine that enables remote code execution under specific conditions. This scripting engine serves as the core JavaScript engine powering Microsoft Edge browser and various other Microsoft applications, making this vulnerability particularly dangerous as it could be exploited across multiple attack vectors. The issue stems from improper handling of objects in memory during script execution, creating opportunities for malicious actors to manipulate memory structures and potentially execute arbitrary code on affected systems. The vulnerability specifically affects ChakraCore versions prior to the security patches released in the August 2018 Microsoft Security Updates, impacting a wide range of Microsoft products that utilize this JavaScript engine for web content processing.
The technical nature of this memory corruption vulnerability places it within the scope of CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which addresses out-of-bounds read vulnerabilities. These classifications reflect the fundamental issue where the ChakraCore engine fails to properly validate object boundaries during memory allocation and access operations. The flaw manifests when the engine processes certain JavaScript objects that trigger memory corruption through improper bounds checking or memory management routines. Attackers can leverage this weakness by crafting malicious JavaScript code that, when executed by the vulnerable ChakraCore engine, causes memory corruption that can be exploited to gain control over the executing process. This type of vulnerability is particularly concerning because it operates at the core engine level, meaning that successful exploitation could bypass many traditional security mechanisms and provide attackers with elevated privileges on the target system.
The operational impact of CVE-2018-0858 extends far beyond simple remote code execution capabilities, as it represents a significant threat to enterprise security environments where Microsoft Edge and related applications are extensively deployed. The vulnerability can be triggered through various attack vectors including malicious websites, email attachments, or any content that utilizes ChakraCore for JavaScript processing. Organizations using Microsoft Edge, Internet Explorer, or applications that embed the ChakraCore engine are at risk, including web applications, Office 365 services, and various Microsoft enterprise solutions. The remote nature of the exploit means that attackers do not require physical access to target systems, allowing for large-scale attacks against multiple endpoints simultaneously. This vulnerability also aligns with ATT&CK technique T1059.007 for Windows Scripting, where adversaries leverage scripting engines to execute malicious code, and T1203 for Exploitation for Client Execution, which describes how attackers use vulnerabilities to execute code on client systems.
Mitigation strategies for CVE-2018-0858 primarily focus on immediate patching and system hardening measures. Microsoft released security updates in August 2018 that address this vulnerability, and organizations should prioritize applying these patches across all affected systems. Additionally, implementing network-level protections such as web application firewalls and content filtering solutions can help reduce exposure by blocking malicious JavaScript content before it reaches vulnerable systems. Browser security configurations should be enhanced through the implementation of strict Content Security Policies and the disabling of unnecessary scripting capabilities where possible. Security monitoring should be enhanced to detect anomalous JavaScript execution patterns that might indicate exploitation attempts, while endpoint protection solutions should be configured to monitor for memory corruption indicators and suspicious process behaviors. Organizations should also consider implementing application whitelisting policies to restrict execution of untrusted JavaScript content and maintain regular vulnerability scanning to identify any remaining instances of the vulnerable ChakraCore engine in their environments. The vulnerability demonstrates the critical importance of maintaining up-to-date security patches and the potential consequences of running outdated software components that may contain known security flaws.