CVE-2021-30581 in Chrome
Summary
by MITRE • 08/04/2021
Use after free in DevTools in Google Chrome prior to 92.0.4515.107 allowed an attacker who convinced a user to install a malicious extension to potentially exploit heap corruption via a crafted HTML page.
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Analysis
by VulDB Data Team • 08/07/2021
The vulnerability identified as CVE-2021-30581 represents a critical use-after-free flaw within the Developer Tools component of Google Chrome browsers. This issue affects versions prior to 92.0.4515.107 and creates a significant security risk that can be exploited through malicious extensions installed by attackers. The vulnerability stems from improper memory management within the DevTools functionality, specifically when handling certain HTML page elements that trigger memory deallocation followed by subsequent access to freed memory regions. The flaw allows an attacker to potentially execute arbitrary code on a victim's system through a carefully crafted HTML page that leverages the compromised DevTools component.
The technical implementation of this vulnerability involves a classic use-after-free condition where memory allocated to DevTools components is freed but not properly invalidated, enabling subsequent access to the same memory location. This memory corruption can occur when a malicious extension interacts with DevTools functionality and triggers specific HTML rendering scenarios that cause the browser to attempt to access freed memory. The attack vector requires social engineering to convince a user to install a malicious extension, which then acts as a delivery mechanism for the exploit. The vulnerability is particularly dangerous because it operates within the browser's privileged context, allowing potential code execution with the same privileges as the browser itself.
From an operational perspective, this vulnerability creates a substantial risk for users who may inadvertently install malicious extensions from untrusted sources. The attack chain typically begins with an extension installation, followed by the execution of a specially crafted HTML page that triggers the memory corruption. The exploit can potentially lead to complete system compromise, allowing attackers to execute arbitrary code, access sensitive data, or escalate privileges. The impact extends beyond individual user systems to enterprise environments where browser-based attacks are common and can serve as initial access vectors for broader network infiltration. Security researchers have classified this vulnerability as high-risk due to its potential for remote code execution and the relatively low barrier to exploitation through social engineering.
Mitigation strategies for CVE-2021-30581 primarily focus on immediate browser updates to versions 92.0.4515.107 and later, which contain the necessary memory management fixes. Organizations should implement strict extension review processes and maintain updated browser security policies that prevent installation of untrusted extensions. Network security controls such as web proxies and content filtering systems can help detect and block malicious HTML content that may trigger this vulnerability. Additionally, users should be educated about the risks of installing extensions from untrusted sources and the importance of maintaining updated browser software. The vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions in software development, and represents a technique that attackers might employ in the exploit phase of the attack lifecycle according to ATT&CK framework category T1059 for command and script interpreter usage. Regular security assessments and penetration testing should include verification of browser versions and extension management policies to ensure comprehensive protection against this class of vulnerability.