CVE-2018-6151 in Chrome
Summary
by MITRE
Bad cast in DevTools in Google Chrome on Win, Linux, Mac, Chrome OS prior to 66.0.3359.117 allowed an attacker who convinced a user to install a malicious extension to perform an out of bounds memory read via a crafted Chrome Extension.
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Analysis
by VulDB Data Team • 06/26/2023
The vulnerability identified as CVE-2018-6151 represents a critical memory safety issue within Google Chrome's Developer Tools component affecting multiple operating systems including Windows, Linux, macOS, and Chrome OS. This flaw manifests as a bad cast condition that occurs during the processing of malicious extensions, creating a pathway for remote code execution through improper memory handling. The vulnerability specifically impacts Chrome versions prior to 66.0.3359.117, making it a significant concern for users running outdated browser versions.
The technical implementation of this vulnerability stems from improper type casting within the DevTools functionality when handling crafted Chrome extensions. When a malicious extension is installed and loaded, the flawed casting operation triggers an out of bounds memory read condition. This memory access violation occurs because the application fails to properly validate or sanitize the extension's data structures before performing type conversions. The issue is categorized under CWE-121 as a buffer overflow condition that arises from improper memory management during type casting operations.
From an operational perspective, this vulnerability creates a severe attack surface that allows adversaries to leverage social engineering tactics to convince users to install malicious extensions. The attack requires only a single user interaction to install the malicious extension, after which the out of bounds read automatically executes without further user input. This makes the vulnerability particularly dangerous in enterprise environments where users may inadvertently install extensions from untrusted sources. The memory read operation can potentially expose sensitive data or provide attackers with information needed to escalate privileges or execute additional malicious code.
The attack vector aligns with ATT&CK technique T1176 which involves the use of malicious browser extensions to maintain persistence and execute code. This vulnerability enables attackers to bypass traditional security controls by leveraging the legitimate browser extension installation process. The impact extends beyond simple information disclosure as the out of bounds memory read could potentially be exploited to achieve arbitrary code execution or privilege escalation depending on the target system configuration. Security researchers have noted that this vulnerability demonstrates the importance of proper input validation and memory safety practices in browser components that handle third-party extensions.
Organizations should immediately update to Chrome version 66.0.3359.117 or later to mitigate this vulnerability, as the patch addresses the underlying casting issue in the DevTools component. Additional mitigation strategies include implementing strict extension installation policies, monitoring for suspicious extension installations, and conducting regular security audits of browser extensions in use. System administrators should also consider deploying browser security extensions that can detect and block malicious extension behavior patterns. The vulnerability serves as a reminder of the critical importance of keeping browser software updated and maintaining comprehensive patch management processes to protect against memory safety vulnerabilities that can lead to remote code execution.