CVE-2017-5032 in Chrome
Summary
by MITRE
PDFium in Google Chrome prior to 57.0.2987.98 for Windows could be made to increment off the end of a buffer, which allowed a remote attacker to potentially exploit heap corruption via a crafted PDF file.
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Analysis
by VulDB Data Team • 12/02/2022
The vulnerability identified as CVE-2017-5032 represents a critical buffer overread condition within PDFium, the PDF rendering engine utilized by Google Chrome on Windows platforms. This flaw existed in Chrome versions prior to 57.0.2987.98 and specifically affected the handling of malformed PDF files that could trigger memory corruption during document processing. The vulnerability stems from inadequate bounds checking during PDF parsing operations, particularly when processing certain embedded data structures within PDF files.
The technical implementation of this vulnerability involves PDFium's failure to properly validate array indices or memory boundaries when processing PDF objects, particularly those related to embedded streams or compressed data sections. When a maliciously crafted PDF file contains specially constructed data that exceeds expected buffer limits, the rendering engine attempts to access memory locations beyond the allocated buffer boundaries. This behavior constitutes a classic heap-based buffer overflow condition that can result in arbitrary code execution or system instability.
From an operational perspective, this vulnerability presents significant risk to Chrome users who may encounter malicious PDF documents through various attack vectors including phishing emails, compromised websites, or malicious file downloads. The remote exploitation capability means that attackers can potentially deliver payloads without requiring local system access, making this a particularly dangerous vulnerability for enterprise environments. The impact extends beyond simple privilege escalation as the heap corruption can lead to complete system compromise when combined with other exploitation techniques.
The vulnerability aligns with CWE-125: "Out-of-bounds Read" and demonstrates characteristics consistent with ATT&CK technique T1203: "Exploitation for Client Execution" where attackers leverage application vulnerabilities to execute malicious code. Security researchers have noted that PDF-based attacks remain prevalent due to the widespread use of PDF readers and the complexity of PDF file structures, making vulnerabilities like CVE-2017-5032 particularly attractive targets for cybercriminals. Organizations should prioritize immediate patching of affected Chrome installations and consider implementing additional security measures such as PDF sandboxing and content filtering to mitigate the risk of exploitation.
The remediation strategy for this vulnerability requires immediate deployment of Chrome version 57.0.2987.98 or later, which includes patches addressing the buffer overread condition in PDFium's parsing routines. Security administrators should also implement network-level controls to restrict access to untrusted PDF content and consider deploying endpoint protection solutions with advanced threat detection capabilities. Regular security assessments should include verification of patched versions and monitoring for potential exploitation attempts through network traffic analysis or endpoint detection and response systems.