CVE-2021-30585 in Chrome
Summary
by MITRE • 08/04/2021
Use after free in sensor handling in Google Chrome on Windows prior to 92.0.4515.107 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-30585 represents a critical use-after-free condition within Google Chrome's sensor handling functionality on Windows operating systems. This flaw exists in versions prior to 92.0.4515.107 and demonstrates how improper memory management can create significant security risks for users. The issue specifically affects Chrome's implementation of sensor APIs that allow web pages to access device sensor data, creating a pathway for remote code execution through maliciously crafted web content.
The technical implementation of this vulnerability stems from inadequate memory management during sensor data processing within Chrome's rendering engine. When a web page attempts to interact with sensor APIs, the browser allocates memory for sensor objects and subsequently frees this memory when the sensor data is no longer needed. However, the code fails to properly validate the state of these memory regions before allowing further access to freed memory blocks. This creates a scenario where an attacker can manipulate the timing and execution flow to access already freed memory locations, leading to heap corruption that can be exploited for arbitrary code execution.
From an operational perspective, this vulnerability presents a severe threat to user security as it enables remote exploitation through standard web browsing activities. Attackers need only craft a malicious HTML page containing specific sensor API calls and deliver it via phishing campaigns, compromised websites, or malicious advertisements. The attack vector is particularly dangerous because it leverages legitimate browser functionality, making it difficult for users to identify the threat. The heap corruption resulting from this use-after-free condition can be leveraged to execute malicious code with the privileges of the Chrome process, potentially leading to full system compromise.
The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in memory management, and represents a classic example of how improper resource handling can create security weaknesses. This flaw also maps to ATT&CK technique T1059.007 for Windows Command Shell execution and T1203 for Exploitation for Client Execution, demonstrating how such memory corruption vulnerabilities can be weaponized for broader attack chains. The impact extends beyond simple privilege escalation as the compromised browser process can potentially access user data, cookies, and other sensitive information stored within the browser environment.
Organizations and users should immediately update to Chrome version 92.0.4515.107 or later to mitigate this vulnerability. Additional mitigations include implementing web application firewalls to filter suspicious sensor API requests, enabling Chrome's sandboxing features, and maintaining comprehensive network monitoring to detect potential exploitation attempts. Security teams should also consider implementing browser hardening measures such as disabling unnecessary sensor APIs for users who do not require them, particularly in high-risk environments. The vulnerability serves as a reminder of the critical importance of proper memory management in browser security and the need for continuous security auditing of complex web platform components.