CVE-2017-5039 in Chrome
Summary
by MITRE
A use after free in PDFium in Google Chrome prior to 57.0.2987.98 for Mac, Windows, and Linux and 57.0.2987.108 for Android 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-2017-5039 represents a critical use-after-free flaw within PDFium, the PDF rendering engine employed by Google Chrome across multiple platforms. This vulnerability exists in versions prior to 57.0.2987.98 for Mac, Windows, and Linux systems, and before 57.0.2987.108 for Android devices, creating a significant security risk for users of these affected browser versions. The flaw specifically manifests in the handling of memory management during PDF document processing, where freed memory objects are still being referenced, potentially leading to exploitable conditions.
The technical nature of this vulnerability falls under the CWE-416 category, which specifically addresses use-after-free conditions where program memory is accessed after it has been freed. In the context of PDFium, this occurs when the renderer processes maliciously crafted PDF files that contain specially constructed objects designed to trigger improper memory deallocation followed by subsequent access to the same memory regions. The flaw exploits the fundamental memory management practices within the PDF rendering pipeline, particularly during the processing of complex PDF elements such as annotations, form fields, or embedded objects that may trigger the problematic code path.
From an operational perspective, this vulnerability enables remote code execution attacks where malicious actors can craft PDF files designed to trigger the heap corruption condition when opened in affected Chrome versions. The attack vector is particularly dangerous as it requires no user interaction beyond opening the malicious document, making it a prime candidate for drive-by download attacks or phishing campaigns. The heap corruption resulting from this use-after-free condition can be leveraged to execute arbitrary code with the privileges of the Chrome process, potentially leading to full system compromise. Security researchers have documented that this vulnerability can be exploited to bypass modern memory protection mechanisms such as address space layout randomization and data execution prevention, making it particularly dangerous in targeted attack scenarios.
The mitigation strategy for CVE-2017-5039 involves immediate upgrade to patched versions of Google Chrome that contain memory management fixes for the PDFium component. Organizations should implement comprehensive patch management procedures to ensure all affected systems are updated promptly, particularly given the remote exploitation capability. Browser vendors and security teams have classified this vulnerability as high severity due to its potential for remote code execution, and the ATT&CK framework categorizes this as a technique for privilege escalation through memory corruption vulnerabilities. Additional defensive measures include implementing content filtering solutions that scan PDF files before delivery, disabling PDF rendering in web browsers for untrusted sources, and deploying network-based intrusion detection systems that can identify suspicious PDF traffic patterns associated with exploitation attempts. The vulnerability also highlights the importance of secure coding practices and memory management validation in widely deployed software components, particularly those handling untrusted input data such as document formats.