CVE-2018-17474 in Chrome
Summary
by MITRE
Use after free in HTMLImportsController in Blink in Google Chrome prior to 70.0.3538.67 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/06/2023
The vulnerability identified as CVE-2018-17474 represents a critical use-after-free condition within the HTMLImportsController component of Blink, the rendering engine that powers Google Chrome and Chromium-based browsers. This flaw exists in versions prior to 70.0.3538.67 and enables remote attackers to potentially exploit heap corruption through maliciously crafted HTML content. The HTMLImportsController is responsible for managing HTML import functionality, which allows developers to include external HTML documents within other HTML documents, creating a hierarchical structure of web components. The vulnerability stems from improper memory management where freed memory blocks are still referenced after being deallocated, creating opportunities for attackers to manipulate heap memory layout and execute arbitrary code.
The technical implementation of this vulnerability involves the manipulation of HTML import operations within the Blink rendering engine. When a web page contains crafted HTML that triggers the HTMLImportsController to process specific import sequences, the controller fails to properly validate memory references during the import lifecycle. This use-after-free condition occurs because the controller maintains references to objects that are freed during the import processing, but these references persist in memory and can be accessed by subsequent operations. The flaw specifically manifests when the HTML import system attempts to clean up imported resources while simultaneously processing new import requests, creating a race condition where memory addresses become available for reuse before all references are properly invalidated.
From an operational perspective, this vulnerability presents significant risks to web application security and user safety. Attackers can craft HTML pages that, when loaded in affected Chrome versions, trigger the use-after-free condition and potentially execute arbitrary code with the privileges of the browser user. The remote exploitation capability means that victims need only visit a malicious website or click on a crafted link to be compromised. This vulnerability can be leveraged for various attack vectors including browser exploitation, privilege escalation, and potentially full system compromise depending on the execution environment. The heap corruption aspect allows attackers to manipulate memory layout and potentially overwrite critical data structures or function pointers, leading to unpredictable behavior or complete system compromise.
The impact of CVE-2018-17474 aligns with CWE-416, which specifically addresses use-after-free vulnerabilities, and can be mapped to several ATT&CK techniques including T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation. The vulnerability's classification as a heap corruption issue also relates to CWE-122, which deals with heap-based buffer overflow conditions. Organizations and users must prioritize immediate patching of affected Chrome versions to mitigate this risk, as the vulnerability affects a core component of web browser security. The remediation approach requires updating to Chrome version 70.0.3538.67 or later, which includes memory management fixes for the HTMLImportsController. Additionally, network security teams should implement web filtering measures and browser hardening configurations to reduce the attack surface while waiting for full patch deployment. The vulnerability demonstrates the critical importance of proper memory management in browser engines and highlights the need for continuous security auditing of core web platform components.