CVE-2020-6378 in Chrome
Summary
by MITRE
Use after free in speech in Google Chrome prior to 79.0.3945.130 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 05/10/2025
The vulnerability identified as CVE-2020-6378 represents a critical use-after-free condition within the speech synthesis functionality of Google Chrome browser versions prior to 79.0.3945.130. This flaw resides in the browser's handling of speech synthesis APIs that enable web applications to convert text to speech output. The issue manifests when the browser processes crafted HTML pages containing malicious speech synthesis code that triggers improper memory management during the speech synthesis process. The underlying technical flaw occurs when the browser's speech synthesis engine attempts to access memory that has already been freed, creating a scenario where arbitrary code execution becomes possible. This vulnerability falls under the CWE-416 category of use-after-free conditions, which is a well-documented class of memory safety issues that can lead to remote code execution when exploited properly. The attack vector requires a remote attacker to craft a malicious HTML page that leverages the browser's speech synthesis capabilities, typically through javascript APIs such as the Web Speech API that Chrome provides for text-to-speech functionality.
The operational impact of CVE-2020-6378 extends beyond simple browser exploitation as it provides attackers with a potential pathway for remote code execution on vulnerable systems. When a user visits a malicious webpage containing the crafted speech synthesis code, the browser's memory corruption occurs during speech processing, potentially allowing attackers to execute arbitrary code with the privileges of the browser process. This represents a significant security risk as it can lead to full system compromise, data exfiltration, or persistence mechanisms being established. The vulnerability demonstrates how seemingly benign browser features like speech synthesis can become attack vectors when proper memory management is not enforced. Attackers can leverage this flaw to bypass modern security mitigations such as address space layout randomization and data execution prevention, especially when the heap corruption results in controlled memory overwrite scenarios. The exploitation typically requires user interaction through visiting a malicious webpage, making this a client-side attack that can be delivered via phishing campaigns or compromised websites.
Mitigation strategies for CVE-2020-6378 primarily focus on immediate browser updates to versions 79.0.3945.130 and later, which contain the necessary patches to address the memory management issue in the speech synthesis component. Organizations should implement comprehensive browser update policies to ensure all users are running patched versions of Chrome. Additional protective measures include implementing content security policies that restrict speech synthesis API usage, disabling unnecessary browser features through group policies, and deploying web application firewalls to filter malicious content. Security teams should monitor for indicators of compromise related to this vulnerability, including unusual speech synthesis API usage patterns or memory corruption behaviors in browser processes. The vulnerability also highlights the importance of regular security assessments of browser APIs and their underlying implementations, particularly for features that interact with system resources. From an ATT&CK framework perspective, this vulnerability maps to techniques involving exploitation of browser vulnerabilities and privilege escalation through memory corruption, potentially enabling adversaries to achieve code execution and persistent access to compromised systems. Organizations should also consider implementing browser sandboxing configurations and network-based detection mechanisms to identify and block exploitation attempts targeting this specific use-after-free condition.