Vulnerability CVE-2024-5830 Identified in Chrome's V8 Engine
/ 3 min read
Quick take - CVE-2024-5830 is a critical type confusion vulnerability in the V8 JavaScript engine of the Chrome browser, allowing for remote code execution through manipulation of object properties and memory, which was addressed in recent Chrome updates.
Fast Facts
- Vulnerability Overview: CVE-2024-5830 is a critical type confusion vulnerability in the V8 JavaScript engine of Chrome, allowing remote code execution (RCE) via malicious websites.
- Impact and Exploitation: The vulnerability can be exploited through object cloning and property accessors, leading to out-of-bounds access and potential arbitrary code execution.
- Technical Mechanism: It involves the manipulation of object maps and transitions, which are essential for optimizing property access in JavaScript, resulting in unexpected dictionary map creation.
- Mitigation: The issue was addressed in Chrome versions 126.0.6478.56 and 126.0.6478.57, highlighting the importance of timely updates for security.
- Security Challenges: The article emphasizes the complexities of maintaining security in modern web browsers, particularly regarding memory management and type confusion vulnerabilities.
CVE-2024-5830: A Significant Vulnerability in the V8 JavaScript Engine
Overview of the Vulnerability
CVE-2024-5830 is a significant type confusion vulnerability identified in the V8 JavaScript engine used by the Chrome browser. This vulnerability was reported in May 2024 and was subsequently addressed in Chrome versions 126.0.6478.56 and 126.0.6478.57. CVE-2024-5830 poses a critical security risk, allowing for remote code execution (RCE) within the renderer sandbox of Chrome. This can potentially be triggered by merely visiting a malicious website.
Understanding the V8 Engine and Object Maps
To understand the vulnerability, the article delves into the workings of object maps and transitions within the V8 engine. Maps, often referred to as hidden classes, are integral to the memory layout of objects in JavaScript. They play a crucial role in optimizing property access. Each map contains an array of property descriptors that outline the properties associated with an object. Maps can be shared among objects that maintain the same property structure.
When a new property is introduced to an object, a new map is generated if an existing one does not correspond to the new layout. Maps can also store multiple transitions, which signify the relationship between old and new maps. Over time, maps can become deprecated, prompting the creation of new maps in response to property assignments.
Exploitation and Security Implications
The vulnerability is exacerbated when a function inadvertently leads to the creation of a dictionary map. Object cloning using spread syntax can trigger this vulnerability, particularly if the cloned object contains a property accessor. The property accessor can result in the deprecation of the map associated with the cloned object, leading to the unexpected formation of a dictionary map. Such an updated dictionary map can create opportunities for out-of-bounds (OOB) access, which can be maliciously exploited.
The article details the process by which an attacker can achieve arbitrary read and write access in the V8 heap through strategic manipulation of object properties and memory. The V8 heap is designed to isolate its memory from other process memory to mitigate the risks of memory corruption. However, methods to escape this heap sandbox are outlined, achieved by modifying API objects that wrap around Blink objects, causing type confusion.
By inducing type confusion between different Blink objects, an attacker can gain arbitrary read and write access to memory, ultimately leading to the capability for arbitrary code execution within the Chrome renderer process. The article further discusses techniques to circumvent Address Space Layout Randomization (ASLR), which is employed to identify useful addresses in process memory.
This vulnerability underscores the ongoing challenges in maintaining security within complex software architectures, particularly evident in modern web browsers.
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