CVE-2017-5127 in Chrome
Summary
by MITRE
Use after free in PDFium in Google Chrome prior to 62.0.3202.62 allowed a remote attacker to potentially exploit heap corruption via a crafted PDF file.
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Analysis
by VulDB Data Team • 02/06/2023
The vulnerability identified as CVE-2017-5127 represents a critical use-after-free condition within the PDFium library component of Google Chrome browsers. This flaw exists in versions prior to 62.0.3202.62 and enables remote attackers to manipulate heap memory through specifically crafted malicious PDF files. The underlying issue stems from improper memory management where freed memory blocks are accessed after being deallocated, creating opportunities for heap corruption that can be exploited to execute arbitrary code on affected systems. This vulnerability directly impacts the browser's PDF rendering functionality and represents a significant security risk for users who may encounter compromised PDF documents.
The technical implementation of this vulnerability involves the PDFium library's handling of memory allocation and deallocation during PDF document processing. When Chrome encounters a malformed PDF file containing maliciously constructed objects, the library fails to properly track memory references, leading to situations where memory addresses are reused after being freed. This memory management error creates a race condition that allows attackers to manipulate the heap structure, potentially overwriting critical data or executing malicious code through controlled memory corruption. The flaw operates at the intersection of memory safety and document parsing, making it particularly dangerous as it leverages legitimate browser functionality to achieve unauthorized code execution.
From an operational impact perspective, this vulnerability exposes users to remote code execution risks when browsing PDF content, making it a prime target for cybercriminals and nation-state actors. The attack vector requires only that a user opens a malicious PDF file, which can be delivered through email attachments, compromised websites, or other social engineering methods. The exploitation potential spans across multiple operating systems where Chrome is deployed, including Windows, macOS, and Linux platforms, amplifying the attack surface. Organizations face significant risk of data breaches, system compromise, and potential lateral movement within networks when this vulnerability is exploited, as successful exploitation can lead to full system control and persistent access.
Security mitigations for CVE-2017-5127 primarily involve immediate patching of Chrome browsers to versions 62.0.3202.62 or later where the memory management issues have been resolved. System administrators should implement comprehensive browser update policies and consider deploying automated patch management solutions to ensure timely remediation. Network defenders can enhance protection through PDF content filtering and sandboxing mechanisms, though these provide only partial mitigation as the vulnerability exists within core browser functionality. The underlying memory safety issue aligns with CWE-416, which describes use-after-free vulnerabilities, and can be mapped to ATT&CK technique T1059.007 for remote code execution through browser-based attacks. Organizations should also implement security awareness training to reduce the risk of users encountering malicious PDF files through social engineering campaigns, as the vulnerability's exploitation requires user interaction with compromised content.