CVE-2018-8557 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-2018-8541, CVE-2018-8542, CVE-2018-8543, CVE-2018-8551, CVE-2018-8555, CVE-2018-8556, CVE-2018-8588.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-8557 represents a critical memory corruption flaw within Microsoft Edge's Chakra scripting engine, which serves as the JavaScript engine powering the browser's web content execution. This vulnerability specifically manifests when the Chakra engine processes objects in memory, creating conditions that can be exploited by malicious actors to execute arbitrary code remotely. The issue affects not only Microsoft Edge but also ChakraCore, which is Microsoft's open-source JavaScript engine used in various applications beyond the browser environment. The vulnerability's classification as a remote code execution flaw places it within the highest severity category, as it allows attackers to gain complete control over affected systems without requiring local access or user interaction beyond visiting a malicious webpage.
The technical root cause of this vulnerability lies in improper memory handling within the Chakra scripting engine's object management system. When the engine processes certain JavaScript objects in memory, it fails to properly validate or sanitize memory operations, leading to memory corruption that can be leveraged to overwrite critical memory locations. This type of vulnerability typically occurs when the engine does not adequately check bounds during object manipulation or fails to properly manage memory allocation and deallocation processes. The flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can lead to memory corruption and arbitrary code execution. The memory corruption vulnerability allows attackers to manipulate the execution flow of the application by overwriting memory addresses with malicious code pointers, effectively bypassing standard security mechanisms.
The operational impact of CVE-2018-8557 extends far beyond simple browser exploitation, as it provides attackers with a powerful vector for system compromise. Once successfully exploited, the vulnerability enables attackers to execute code with the privileges of the Edge process, which typically runs with limited user privileges but can still provide access to sensitive system resources. The vulnerability's remote nature means that attackers can deliver malicious payloads through compromised websites, phishing emails containing malicious links, or even through compromised advertising networks. The attack surface is particularly concerning given that Microsoft Edge was widely deployed across enterprise environments, making organizations vulnerable to targeted attacks that could escalate to full system compromise. This vulnerability aligns with ATT&CK technique T1059.007, which covers script-based attacks using JavaScript, and T1068, which involves local privilege escalation through exploitation of system vulnerabilities.
Mitigation strategies for CVE-2018-8557 should focus on immediate patch deployment and layered security approaches. Microsoft released security updates addressing this vulnerability through regular security bulletins, and organizations should prioritize applying these patches to all affected systems. Network-based mitigations can include implementing web application firewalls, content filtering solutions, and restricting access to potentially malicious websites. Browser hardening measures such as disabling unnecessary JavaScript features, implementing strict content security policies, and using sandboxing technologies can significantly reduce the attack surface. Organizations should also consider implementing monitoring solutions that can detect anomalous JavaScript execution patterns or memory access violations that might indicate exploitation attempts. Additionally, security teams should conduct regular vulnerability assessments to identify systems running outdated versions of Edge or ChakraCore that may still be vulnerable to this or related memory corruption vulnerabilities, ensuring comprehensive protection against similar threats in the future.