CVE-2020-16019 in Chrome
Summary
by MITRE • 01/09/2021
Inappropriate implementation in filesystem in Google Chrome on ChromeOS prior to 87.0.4280.66 allowed a remote attacker who had compromised the browser process to bypass noexec restrictions via a malicious file.
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Analysis
by VulDB Data Team • 05/04/2025
This vulnerability resides in the filesystem implementation of Google Chrome running on ChromeOS systems, specifically affecting versions prior to 87.0.4280.66. The flaw represents an inadequate security control that allows a remote attacker who has already compromised the browser process to circumvent noexec restrictions, which are fundamental memory protection mechanisms designed to prevent code execution from data pages. The vulnerability manifests through malicious file manipulation that exploits improper validation or enforcement of memory protection boundaries within the ChromeOS filesystem handling code.
The technical nature of this flaw involves a failure in the kernel-level memory management subsystem where the noexec bit protections are not properly enforced when processing certain file operations. This creates a privilege escalation path where an attacker who has already gained control of the browser process can leverage this vulnerability to execute arbitrary code in contexts where such execution would normally be prohibited. The vulnerability is particularly concerning because it operates at the intersection of process compromise and memory protection bypass, allowing attackers to escalate their privileges beyond what would normally be possible within the ChromeOS security model.
From an operational perspective, this vulnerability significantly weakens the security posture of ChromeOS devices by undermining the fundamental principle of process isolation and memory protection. The attack scenario typically begins with a successful browser process compromise through other means, followed by exploitation of this filesystem vulnerability to gain elevated privileges. This creates a dangerous escalation path where attackers can move from a compromised browser context to potentially full system control, bypassing the layered security protections that ChromeOS relies upon to protect against code injection attacks and privilege escalation attempts.
The impact of this vulnerability extends beyond simple privilege escalation as it demonstrates a failure in the security model's defense-in-depth approach. The noexec restrictions are a core component of modern operating system security architectures, designed to prevent buffer overflow exploits and other code injection techniques from succeeding. When these protections can be bypassed through filesystem manipulation, it indicates a critical weakness in the kernel's security implementation. This vulnerability aligns with CWE-119, which covers "Improper Access to Resources via Buffer Overflow," and represents a failure in memory protection enforcement mechanisms that would typically be addressed through proper kernel security architecture and input validation.
Mitigation strategies for this vulnerability require immediate system updates to ChromeOS versions 87.0.4280.66 or later where the filesystem implementation has been corrected. Organizations should implement comprehensive monitoring for suspicious file operations and memory access patterns that could indicate exploitation attempts. The fix likely involves strengthening the validation of file access permissions and ensuring that noexec protections are properly enforced during filesystem operations, particularly those involving dynamically loaded content or user-supplied files. Security teams should also consider implementing additional runtime protections and behavioral monitoring to detect potential exploitation attempts, as this vulnerability represents a sophisticated attack vector that could be used in targeted campaigns against high-value ChromeOS deployments.