CVE-2017-5034 in Chrome
Summary
by MITRE
A use after free in PDFium in Google Chrome prior to 57.0.2987.98 for Linux and Windows 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 • 12/02/2022
The vulnerability identified as CVE-2017-5034 represents a critical use after free condition within the PDFium library component of Google Chrome browser versions prior to 57.0.2987.98 on Linux and Windows platforms. This flaw exists in the handling of PDF documents and provides a remote code execution vector through crafted malicious PDF files that can be delivered via web pages or email attachments. The vulnerability specifically affects the memory management operations within the PDF rendering engine, where freed memory blocks are subsequently accessed without proper validation, creating opportunities for attackers to manipulate program execution flow.
The technical implementation of this vulnerability stems from improper memory deallocation and subsequent access patterns within the PDFium library's object handling mechanisms. When processing certain PDF files containing malformed or specially crafted objects, the library releases memory blocks back to the system but fails to properly invalidate references to these locations. Attackers can exploit this by creating PDF documents that trigger specific memory allocation sequences, causing the application to read from memory locations that have already been freed. This particular flaw manifests as an out of bounds memory read operation, allowing attackers to potentially access sensitive data or execute arbitrary code within the context of the browser process.
The operational impact of CVE-2017-5034 extends beyond simple remote code execution capabilities, as it enables sophisticated attack vectors that can bypass modern security mitigations such as address space layout randomization and data execution prevention. The vulnerability's exploitation requires minimal user interaction beyond visiting a malicious webpage or opening a compromised PDF document, making it particularly dangerous in phishing campaigns or drive-by download scenarios. Security researchers have classified this issue under CWE-416, which specifically addresses use after free vulnerabilities, and it maps to ATT&CK technique T1059.007 for remote code execution through browser exploits. The vulnerability affects users across multiple operating systems, with Linux and Windows versions being particularly susceptible due to differences in memory management implementations between these platforms.
Mitigation strategies for CVE-2017-5034 primarily focus on immediate browser updates to versions 57.0.2987.98 or later, which contain patches addressing the memory management issues within PDFium. Organizations should implement comprehensive patch management policies to ensure all systems receive timely updates, particularly given the remote nature of the exploit. Additional protective measures include deploying web application firewalls that can detect and block suspicious PDF content, implementing strict browser sandboxing configurations, and utilizing privilege separation techniques to limit potential damage from successful exploitation attempts. Security teams should also consider network-based intrusion detection systems that can identify patterns associated with known exploit signatures for this vulnerability, while maintaining awareness of the broader threat landscape for similar memory corruption vulnerabilities that may be leveraged in conjunction with CVE-2017-5034.