CVE-2019-5755 in Chrome
Summary
by MITRE
Incorrect handling of negative zero in V8 in Google Chrome prior to 72.0.3626.81 allowed a remote attacker to perform arbitrary read/write via a crafted HTML page.
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Analysis
by VulDB Data Team • 07/11/2023
The vulnerability identified as CVE-2019-5755 represents a critical flaw in the V8 JavaScript engine used by Google Chrome prior to version 72.0.3626.81. This issue stems from improper handling of negative zero values within the engine's mathematical operations and type conversion mechanisms. The vulnerability specifically manifests when the V8 engine processes JavaScript code that involves negative zero in arithmetic operations or comparisons, creating a condition where the engine fails to properly distinguish between positive and negative zero values during internal computations.
The technical exploitation of this vulnerability occurs through a crafted HTML page that leverages JavaScript code designed to manipulate negative zero values in ways that trigger memory access violations. When the V8 engine processes such malicious code, it can cause the engine to incorrectly interpret memory addresses or manipulate internal data structures, leading to arbitrary read and write capabilities. This behavior stems from the engine's failure to properly implement IEEE 754 floating-point arithmetic standards, particularly in how it handles the distinction between positive and negative zero values during mathematical operations.
The operational impact of this vulnerability is severe as it allows remote attackers to execute arbitrary code on affected systems without user interaction. An attacker could craft a malicious webpage that when loaded in a vulnerable Chrome browser would enable them to read arbitrary memory locations, write to memory regions, and potentially execute arbitrary code with the privileges of the browser process. This creates a significant threat vector for phishing attacks, drive-by downloads, and other remote exploitation scenarios where attackers can leverage the vulnerability to gain unauthorized access to systems.
The vulnerability aligns with CWE-128, which describes "Wrap or Overflow" conditions in integer operations, and also relates to CWE-787, "Out-of-bounds Write," as the improper handling of negative zero can lead to memory corruption. From an ATT&CK framework perspective, this vulnerability maps to technique T1059.007 for JavaScript execution and T1070.004 for bypassing security controls through memory corruption. The flaw demonstrates how seemingly minor implementation details in mathematical operations can create significant security risks when they interact with memory management and code execution pathways.
Mitigation strategies for this vulnerability require immediate patching of Chrome browsers to version 72.0.3626.81 or later, which includes fixes to the V8 engine's handling of negative zero values. Organizations should also implement network-based protections such as web application firewalls and content filtering systems that can detect and block malicious JavaScript patterns. Browser hardening measures including disabling unnecessary JavaScript features, implementing strict content security policies, and using sandboxing techniques can further reduce the attack surface. Additionally, regular security updates and vulnerability assessments should be conducted to ensure all browser components remain protected against similar implementation flaws in floating-point arithmetic handling.