CVE-2016-5216 in Chrome
Summary
by MITRE
A use after free in PDFium in Google Chrome prior to 55.0.2883.75 for Mac, Windows and Linux, and 55.0.2883.84 for Android allowed a remote attacker to perform an out of bounds memory read via a crafted PDF file.
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Analysis
by VulDB Data Team • 05/14/2026
The vulnerability identified as CVE-2016-5216 represents a critical use after free condition within PDFium, the PDF rendering engine integrated into Google Chrome browser across multiple platforms. This flaw existed in Chrome versions prior to 55.0.2883.75 for macOS, Windows, and Linux systems, and 55.0.2883.84 for Android devices, creating a significant security risk for users who encountered maliciously crafted PDF documents. The vulnerability stems from improper memory management during PDF processing operations, specifically when handling certain PDF objects that trigger memory deallocation followed by subsequent access to freed memory locations.
The technical exploitation of this vulnerability involves a remote attacker crafting a malicious PDF file that, when opened in the affected Chrome versions, triggers the use after free condition within the PDFium component. This particular flaw manifests as an out of bounds memory read operation, where the application attempts to access memory locations that have already been freed and potentially reallocated. The underlying cause falls under CWE-416, which specifically addresses the use of freed memory conditions, and can be categorized under the broader ATT&CK technique T1203 for exploitation of software vulnerabilities. When a victim opens the crafted PDF, the PDFium engine processes the document structure and encounters specific object sequences that lead to memory deallocation followed by unauthorized memory access.
The operational impact of CVE-2016-5216 extends beyond simple information disclosure, as it provides attackers with potential avenues for more sophisticated attacks including arbitrary code execution. While the immediate effect is an out of bounds memory read, the use after free condition creates a fundamental memory corruption vulnerability that attackers can potentially leverage to gain control over the browser process. This vulnerability affects a broad user base since Chrome is one of the most widely used web browsers globally, and PDF files are commonly encountered in email attachments, web downloads, and various digital documents. The cross-platform nature of the vulnerability means that users on macOS, Windows, Linux, and Android devices are all at risk, making it particularly dangerous for enterprise environments where diverse operating systems coexist.
Mitigation strategies for CVE-2016-5216 primarily focus on immediate remediation through software updates, with users and administrators urged to upgrade to Chrome versions 55.0.2883.75 or later for desktop platforms and 55.0.2883.84 for Android systems. Organizations should implement comprehensive patch management procedures to ensure all affected systems receive updates promptly, as the vulnerability can be exploited without user interaction once a malicious PDF is opened. Additional protective measures include implementing PDF sandboxing features, restricting PDF file handling through email security solutions, and deploying network-based intrusion detection systems that can identify suspicious PDF content. Security teams should also consider deploying web application firewalls that can filter potentially malicious PDF content and establish monitoring procedures to detect unusual PDF processing activities that might indicate exploitation attempts. The vulnerability highlights the critical importance of memory safety in browser components and reinforces the necessity of regular security updates and proactive vulnerability management programs.