CVE-2018-8145 in Internet Explorer
Summary
by MITRE
An information disclosure vulnerability exists when Chakra improperly discloses the contents of its memory, which could provide an attacker with information to further compromise the user's computer or data, aka "Chakra Scripting Engine Memory Corruption Vulnerability." This affects ChakraCore, Internet Explorer 11, Microsoft Edge, Internet Explorer 10. This CVE ID is unique from CVE-2018-0943, CVE-2018-8130, CVE-2018-8133, CVE-2018-8177.
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Analysis
by VulDB Data Team • 09/11/2025
The vulnerability described in CVE-2018-8145 represents a critical information disclosure flaw within Microsoft's Chakra scripting engine, which serves as the JavaScript engine powering Internet Explorer and Microsoft Edge browsers. This vulnerability specifically manifests as improper memory handling that allows attackers to access sensitive memory contents through flawed memory management operations. The Chakra engine, designed to execute JavaScript code efficiently, contains a flaw that enables unauthorized memory access patterns, potentially exposing confidential data stored in memory regions that should remain protected from user-space applications. The vulnerability affects multiple Microsoft products including ChakraCore, Internet Explorer 11, and Microsoft Edge, making it particularly dangerous as it spans across different browser implementations and versions. The issue falls under the CWE-200 category of "Information Exposure" and aligns with ATT&CK technique T1059.007 for "Scripting" as it leverages scripting engine vulnerabilities to extract information. This flaw represents a fundamental breakdown in the memory isolation mechanisms that should protect sensitive data from unauthorized access, creating opportunities for attackers to gather information that could be used for subsequent exploitation attempts.
The technical implementation of this vulnerability involves memory corruption patterns that occur during JavaScript execution within the Chakra engine. When processing certain JavaScript code sequences, the engine fails to properly validate memory access operations, leading to situations where memory addresses containing sensitive information can be inadvertently exposed to attackers. This memory disclosure occurs through improper handling of object references and memory layout management within the JavaScript engine's memory allocator. The flaw specifically affects how the engine manages memory during dynamic object creation and manipulation, where memory regions that should be protected or properly deallocated become accessible through crafted JavaScript payloads. Attackers can leverage this vulnerability by constructing specific JavaScript code that triggers the memory corruption, allowing them to read memory contents that contain sensitive information such as cryptographic keys, user credentials, or other confidential data stored in memory. The vulnerability's impact extends beyond simple information disclosure as it provides attackers with the foundational information needed to perform more sophisticated attacks such as exploit development, privilege escalation, or data exfiltration operations.
The operational impact of CVE-2018-8145 is significant as it creates opportunities for attackers to gather intelligence that can be used in advanced persistent threat campaigns. The information disclosed through this vulnerability can include memory addresses, stack contents, or other sensitive data that can be leveraged to bypass security mechanisms such as address space layout randomization or data execution prevention. This information disclosure capability makes the vulnerability particularly dangerous for targeted attacks where attackers need specific memory layout information to develop more effective exploits. The vulnerability affects widely used browser applications, meaning that successful exploitation could compromise a large number of systems across different organizations. The impact extends to both enterprise and consumer environments, as Internet Explorer 10 and Internet Explorer 11 continue to be used in various corporate environments. The vulnerability's presence in ChakraCore also indicates potential impacts on Node.js applications and other software that relies on the Chakra engine for JavaScript execution. Organizations may experience increased risk of credential theft, data breaches, or privilege escalation attacks when this vulnerability is exploited in the wild. The vulnerability's classification as a memory corruption issue also means that it can potentially be chained with other vulnerabilities to create more powerful attack vectors.
Mitigation strategies for CVE-2018-8145 should focus on both immediate defensive measures and long-term architectural improvements. Microsoft has released security updates that address this vulnerability through patches that correct the memory handling behavior within the Chakra engine. Organizations should prioritize applying these security updates immediately to protect their systems from exploitation attempts. Additionally, implementing network-level protections such as web application firewalls and content security policies can help detect and block exploitation attempts targeting this vulnerability. Browser hardening techniques including disabling unnecessary JavaScript features, implementing strict memory access controls, and using sandboxing mechanisms can further reduce the attack surface. Security monitoring should include detection of anomalous JavaScript execution patterns that might indicate exploitation attempts, particularly around memory access operations. The vulnerability highlights the importance of proper memory management in scripting engines and underscores the need for regular security assessments of core software components. Organizations should also consider implementing principle of least privilege controls and regular security audits to identify similar vulnerabilities in other software components. The ATT&CK framework suggests that this vulnerability should be monitored for potential use in initial access phases of attacks, particularly in phishing campaigns targeting browser-based exploits, making comprehensive threat hunting and incident response procedures essential for effective mitigation.