CVE-2018-8556 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-2018-8557, CVE-2018-8588.
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Analysis
by VulDB Data Team • 06/05/2023
The CVE-2018-8556 vulnerability represents a critical memory corruption flaw within Microsoft Edge's Chakra scripting engine, which serves as the JavaScript engine powering the browser's execution environment. This vulnerability specifically manifests when the Chakra engine processes certain objects in memory, creating conditions that allow attackers to manipulate memory layout and execute arbitrary code remotely. The issue stems from improper handling of object references and memory management within the scripting engine's runtime environment, making it particularly dangerous for web-based attack scenarios. The vulnerability affects not only Microsoft Edge but also ChakraCore, which is Microsoft's open-source JavaScript engine used in various applications beyond the browser, including Node.js applications and Windows applications.
The technical exploitation of this vulnerability occurs through memory corruption techniques that leverage the Chakra engine's object handling mechanisms. When malicious JavaScript code is executed within Edge, the engine's memory management routines fail to properly validate object states, leading to buffer overflows or use-after-free conditions. These memory corruption issues can be triggered by crafting specific JavaScript code that manipulates object references in ways that bypass normal safety checks. The vulnerability's classification as a remote code execution flaw means that attackers can exploit it through web pages without requiring local system access, making it particularly dangerous in phishing campaigns or compromised websites. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios, both of which are common patterns in memory corruption exploits.
The operational impact of CVE-2018-8556 extends beyond simple browser compromise, as successful exploitation can lead to complete system takeover through the execution of arbitrary code with the privileges of the Edge process. Attackers can leverage this vulnerability to install malware, steal sensitive data, or establish persistent access to affected systems. The vulnerability's presence in both Edge and ChakraCore creates a broader attack surface since ChakraCore is integrated into multiple Microsoft products and third-party applications that use the engine. This cross-platform impact makes the vulnerability particularly concerning for enterprise environments where Edge is used for web browsing and where ChakraCore might be embedded in applications that handle untrusted web content. The remote nature of the exploit means that victims can be compromised simply by visiting malicious websites, making it a prime target for automated attacks and large-scale campaigns.
Mitigation strategies for CVE-2018-8556 should prioritize immediate patching of affected systems, as Microsoft released security updates to address the memory corruption issues within the Chakra engine. Organizations should implement network-based protections such as web application firewalls and content filtering solutions to block known malicious JavaScript patterns that could trigger the vulnerability. Browser hardening techniques including sandboxing, strict content security policies, and disabling unnecessary scripting features can reduce the attack surface. Additionally, security monitoring should focus on detecting anomalous JavaScript execution patterns and memory access violations that might indicate exploitation attempts. The vulnerability's characteristics align with ATT&CK technique T1059.007, which covers JavaScript execution, and T1068, which deals with exploit development for local privilege escalation, making comprehensive endpoint detection and response capabilities essential for identifying and containing exploitation attempts. Regular security assessments should verify that all systems using Chakra-based components have been properly updated and that security configurations are enforced across all affected platforms.