CVE-2011-0475 in Chrome
Summary
by MITRE
Use-after-free vulnerability in Google Chrome before 8.0.552.237 and Chrome OS before 8.0.552.344 allows remote attackers to cause a denial of service or possibly have unspecified other impact via a PDF document.
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Analysis
by VulDB Data Team • 10/12/2021
The vulnerability identified as CVE-2011-0475 represents a critical use-after-free flaw in Google Chrome browser versions prior to 8.0.552.237 and Chrome OS versions before 8.0.552.344. This type of vulnerability occurs when a program continues to reference memory that has already been freed, creating a dangerous condition that can be exploited by malicious actors. The specific context of this flaw involves Chrome's handling of PDF documents, which are commonly encountered in web browsing environments and represent a significant attack surface due to their complex binary formats and rich feature sets. The vulnerability is particularly concerning because it can be triggered through remote PDF documents, making it an attractive target for attackers who can deliver malicious payloads through web pages or email attachments containing crafted PDF files.
The technical implementation of this use-after-free vulnerability stems from improper memory management within Chrome's PDF rendering engine. When processing maliciously crafted PDF documents, the browser fails to properly validate memory references, leading to situations where freed memory blocks are accessed or reused before proper deallocation occurs. This flaw allows attackers to manipulate the memory layout of the browser process, potentially enabling arbitrary code execution or system compromise. The vulnerability's classification as a use-after-free aligns with CWE-416, which specifically addresses the reuse of freed memory resources, and represents a common pattern in browser security exploits that leverage memory corruption vulnerabilities. Attackers can exploit this condition by crafting PDF documents that trigger the vulnerable code path, causing the browser to access freed memory locations and potentially execute malicious code in the context of the browser process.
The operational impact of CVE-2011-0475 extends beyond simple denial of service scenarios to potentially enable full system compromise. While the vulnerability description mentions possible unspecified other impacts, the nature of use-after-free conditions typically allows for more severe consequences including arbitrary code execution, privilege escalation, and complete system takeover. Remote attackers can leverage this vulnerability without requiring user interaction beyond visiting a malicious webpage containing the crafted PDF document. The risk is amplified by the widespread adoption of Google Chrome and the prevalence of PDF documents in both legitimate business environments and malicious attack vectors. Organizations running affected browser versions face significant exposure, as the vulnerability can be exploited through various attack vectors including phishing campaigns, malicious advertisements, and compromised websites. The exploitability factor is enhanced by the fact that PDF processing is a common browser function, making the attack surface readily accessible to threat actors.
Mitigation strategies for CVE-2011-0475 primarily focus on immediate remediation through software updates. The most effective approach involves upgrading to Google Chrome version 8.0.552.237 or later and Chrome OS version 8.0.552.344 or later, which contain the necessary patches to address the memory management issues. System administrators should implement comprehensive patch management procedures to ensure all affected systems receive updates promptly. Additional protective measures include implementing web content filtering solutions that can block or sandbox PDF content, configuring browser security settings to disable automatic PDF processing, and deploying intrusion detection systems to monitor for exploitation attempts. Organizations should also consider implementing application whitelisting policies that restrict PDF processing to trusted applications and environments. The vulnerability demonstrates the importance of maintaining up-to-date browser security and highlights the need for regular security assessments of web-based applications. From an ATT&CK framework perspective, this vulnerability maps to techniques involving code injection and privilege escalation through memory corruption, making it a significant concern for organizations seeking to maintain robust cybersecurity postures.