CVE-2019-5786 in Chrome
Summary
by MITRE
Object lifetime issue in Blink in Google Chrome prior to 72.0.3626.121 allowed a remote attacker to potentially perform out of bounds memory access via a crafted HTML page.
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Analysis
by VulDB Data Team • 11/14/2025
The vulnerability identified as CVE-2019-5786 represents a critical object lifetime management flaw within the Blink rendering engine that powers Google Chrome. This issue stems from improper handling of object references and memory allocation patterns that can lead to dangerous memory access conditions. The vulnerability exists in the way Blink manages the lifecycle of JavaScript objects and DOM elements, creating potential opportunities for memory corruption that could be exploited remotely.
The technical implementation of this vulnerability involves a specific race condition or memory management error that occurs during the object destruction phase of Blink's rendering process. When processing crafted HTML content, the engine fails to properly track object references, leading to scenarios where memory locations may be accessed after they have been freed or reallocated. This type of memory safety issue falls under the category of out-of-bounds memory access as defined by CWE-125, which specifically addresses the access of memory locations beyond the bounds of allocated buffers. The flaw manifests when the browser encounters maliciously constructed HTML that triggers improper object cleanup sequences.
From an operational perspective, this vulnerability creates a significant risk for remote code execution capabilities when exploited. Attackers can craft HTML pages that, when loaded in Chrome, trigger the memory corruption conditions that lead to arbitrary code execution. The attack surface is particularly concerning because it requires no user interaction beyond visiting a malicious webpage, making it a prime target for drive-by download attacks and phishing campaigns. The vulnerability affects all versions of Chrome prior to 72.0.3626.121, representing a substantial user base that would be exposed to this risk.
The exploitation of CVE-2019-5786 aligns with several techniques documented in the MITRE ATT&CK framework, particularly within the initial access and execution phases of attack chains. The vulnerability enables adversaries to leverage web-based attack vectors that bypass traditional security controls, as the exploit operates entirely within the browser's rendering context. This type of vulnerability is especially dangerous because it can be delivered through standard web content and does not require any special privileges or local system access. Security researchers have noted that the memory corruption patterns associated with this issue can be leveraged to achieve privilege escalation or information disclosure, depending on the execution environment and target system configuration.
Mitigation strategies for this vulnerability focus primarily on immediate browser updates to versions 72.0.3626.121 and later, which contain the necessary patches to address the object lifetime management issues. Organizations should implement comprehensive patch management policies that prioritize updates to browser software, particularly for enterprise environments where multiple users may be exposed to web-based threats. Additional defensive measures include implementing web application firewalls, content security policies, and restricting access to potentially malicious websites through browser-based security controls. The remediation efforts should also include monitoring for indicators of compromise related to this vulnerability, such as unusual memory access patterns or unexpected browser behavior that might suggest exploitation attempts.