CVE-2016-5198 in Chrome
Summary
by MITRE
V8 in Google Chrome prior to 54.0.2840.90 for Linux, and 54.0.2840.85 for Android, and 54.0.2840.87 for Windows and Mac included incorrect optimisation assumptions, which allowed a remote attacker to perform arbitrary read/write operations, leading to code execution, via a crafted HTML page.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/29/2025
The vulnerability identified as CVE-2016-5198 represents a critical optimization flaw within Google Chrome's V8 JavaScript engine that affected multiple platform versions prior to specific patch releases. This issue stems from incorrect assumptions made during the Just-In-Time compilation process where the V8 engine optimizes JavaScript code execution by making assumptions about object layouts and memory access patterns. The flaw specifically manifests in how the engine handles certain object property access patterns during optimization phases, creating a condition where memory corruption can occur when malicious JavaScript code attempts to manipulate object structures in ways that contradict the optimization assumptions. The vulnerability impacts Chrome versions 54.0.2840.90 and earlier on Linux, 54.0.2840.85 and earlier on Android, and 54.0.2840.87 and earlier on Windows and Mac platforms, making it a widespread concern across Google's cross-platform browser ecosystem.
The technical exploitation of this vulnerability occurs through a carefully crafted HTML page that leverages the flawed optimization logic to achieve arbitrary read and write operations within the browser's memory space. When the V8 engine encounters specific JavaScript patterns during optimization, it makes incorrect assumptions about object layouts that result in memory addresses being manipulated in unexpected ways. Attackers can construct malicious JavaScript code that triggers these optimization paths, causing the engine to execute code that can read from or write to arbitrary memory locations. This memory corruption enables attackers to bypass modern security protections like address space layout randomization and data execution prevention mechanisms, ultimately allowing for code execution within the browser context. The flaw operates at the intersection of compiler optimization and memory safety, where the optimization process itself becomes a vector for exploitation rather than a performance enhancement.
The operational impact of CVE-2016-5198 extends beyond simple browser compromise, as it represents a sophisticated technique for achieving arbitrary code execution that can be leveraged in various attack scenarios. The vulnerability can be exploited through web-based attack vectors without requiring user interaction beyond visiting a malicious website, making it particularly dangerous for phishing campaigns and drive-by download attacks. The arbitrary read/write capabilities enable attackers to manipulate browser processes, potentially leading to privilege escalation, data theft, or further system compromise. Security researchers have classified this vulnerability under CWE-121, heap-based buffer overflow, and it aligns with ATT&CK technique T1059.007 for JavaScript-based execution, demonstrating how optimization flaws can create persistent security risks that are difficult to detect through conventional security measures. The vulnerability's impact is amplified by its presence in widely used browser versions across multiple operating systems, providing attackers with broad exploitation opportunities.
Mitigation strategies for CVE-2016-5198 primarily focus on immediate patching of affected Chrome versions, as Google released security updates that addressed the optimization assumptions leading to the vulnerability. Organizations should prioritize updating to Chrome versions 54.0.2840.90 for Linux, 54.0.2840.85 for Android, and 54.0.2840.87 for Windows and Mac platforms. Additional defensive measures include implementing content security policies to restrict script execution, deploying web application firewalls to monitor and block suspicious JavaScript patterns, and utilizing browser hardening techniques such as disabling unnecessary JavaScript features. Security monitoring should focus on detecting unusual memory access patterns and JavaScript execution that might indicate exploitation attempts, while network-based detection systems should be configured to identify malicious HTML pages containing known exploit patterns. The vulnerability underscores the importance of continuous security testing of compiler optimization paths and the need for robust memory safety mechanisms in high-performance JavaScript engines, as the trade-off between performance and security must be carefully managed to prevent such critical flaws from being exploited in the wild.