CVE-2018-8387 in Edge
Summary
by MITRE
A remote code execution vulnerability exists when Microsoft Edge improperly accesses objects in memory, aka "Microsoft Edge Memory Corruption Vulnerability." This affects Microsoft Edge. This CVE ID is unique from CVE-2018-8377.
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Analysis
by VulDB Data Team • 03/15/2020
The vulnerability identified as CVE-2018-8387 represents a critical memory corruption flaw in Microsoft Edge browser that enables remote code execution under specific conditions. This vulnerability specifically manifests when the Edge rendering engine fails to properly validate object references in memory, creating opportunities for malicious actors to exploit memory handling mechanisms. The issue stems from improper memory management during object lifecycle operations within the browser's JavaScript engine, which processes web content and executes scripts. Attackers can leverage this weakness by crafting malicious web pages that trigger the vulnerable code path, leading to arbitrary code execution on affected systems. The vulnerability affects Microsoft Edge versions prior to the security update released in August 2018, making it particularly dangerous given Edge's widespread adoption across enterprise environments and user bases. This type of memory corruption vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where programs access memory locations beyond allocated boundaries, and also relates to CWE-787, concerning out-of-bounds writes that can overwrite adjacent memory regions. From an operational perspective, this vulnerability presents significant risk to organizations since Edge browsers are commonly used for internal business applications and web-based services. The remote exploitation capability means attackers can compromise systems simply by having users visit malicious websites or receive compromised emails containing links to malicious content. The attack surface expands when considering that Edge integrates with various Windows components and services, potentially allowing attackers to escalate privileges and move laterally within networks. The vulnerability's classification as a remote code execution flaw places it within the ATT&CK framework under the T1059 technique category, specifically targeting execution through script-based attacks. Organizations face substantial operational impact including potential data breaches, system compromise, and disruption of business continuity. The attack vector typically involves social engineering campaigns where users are诱导ed to visit malicious websites, making user awareness and security training critical components of defense. Additionally, the vulnerability's exploitation often requires no user interaction beyond visiting a compromised website, making it particularly insidious for enterprise environments where users frequently access web content from untrusted sources.
The technical implementation of this memory corruption vulnerability involves sophisticated manipulation of JavaScript object references within Edge's memory space. When Edge processes certain JavaScript constructs, particularly those involving object creation, deletion, and reference management, it fails to properly validate memory boundaries during these operations. This allows attackers to craft specific JavaScript code patterns that cause the browser to access invalid memory locations, potentially leading to memory corruption that can be exploited to execute arbitrary code. The vulnerability demonstrates characteristics of heap-based memory corruption where attackers can manipulate heap metadata to redirect execution flow or overwrite critical program structures. Microsoft's security advisory indicates that the flaw occurs during the handling of specific JavaScript objects, particularly those involving array operations and object property access. The exploitation process typically involves multiple stages including memory layout discovery, payload delivery, and execution shellcode that bypasses modern security mitigations such as address space layout randomization and data execution prevention. The vulnerability's impact extends beyond immediate code execution to potentially enable privilege escalation attacks, especially when combined with other exploitation techniques. Security researchers have noted that the vulnerability can be chained with other exploits to create more sophisticated attack vectors. The complexity of the exploit requires significant technical knowledge and often involves custom exploit development to successfully compromise target systems. Organizations must understand that this vulnerability represents a fundamental flaw in the browser's memory management system that affects all versions prior to the applicable security patch. The remediation process requires immediate deployment of Microsoft's security updates, which typically include memory validation fixes and enhanced object lifecycle management within the Edge rendering engine. Network segmentation and web filtering solutions can provide temporary mitigation while full patches are deployed, though these measures may not prevent all exploitation attempts. The vulnerability's discovery and disclosure prompted Microsoft to enhance their browser security testing methodologies, particularly focusing on memory safety and object management in JavaScript engines. This case study demonstrates the critical importance of memory safety in modern web browsers and the potential for seemingly minor implementation flaws to create significant security risks. The vulnerability's characteristics make it particularly challenging to detect through standard network monitoring or endpoint protection solutions, requiring specialized security tools and proactive threat hunting approaches to identify potential exploitation attempts. Organizations should implement comprehensive vulnerability management processes that prioritize browser security patches, as this vulnerability represents a classic example of how browser-based attacks can bypass traditional network security controls.