CVE-2018-3959 in Foxit
Summary
by MITRE
A use-after-free vulnerability exists in the JavaScript engine of Foxit Software's Foxit PDF Reader version 9.1.0.5096. A use-after-free condition can occur when accessing the Author property of the this.info object. An attacker needs to trick the user to open the malicious file to trigger this vulnerability. If the browser plugin extension is enabled, visiting a malicious site can also trigger the vulnerability.
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Analysis
by VulDB Data Team • 07/30/2024
The vulnerability identified as CVE-2018-3959 represents a critical use-after-free condition within Foxit Software's PDF Reader application, specifically affecting version 9.1.0.5096. This flaw exists within the JavaScript engine component that processes PDF documents, creating a dangerous scenario where memory that has been freed is still being accessed by the application. The vulnerability manifests when the application attempts to access the Author property of the this.info object, which triggers improper memory management behavior that can lead to arbitrary code execution. The security implications are severe as this type of vulnerability can be exploited to gain complete control over the victim's system.
The technical nature of this vulnerability aligns with CWE-416, which specifically addresses use-after-free conditions where software attempts to access memory after it has been freed. This particular flaw occurs in the JavaScript engine's handling of PDF metadata objects, particularly when processing the info dictionary that contains document information such as author, title, and other metadata fields. The vulnerability is triggered through the manipulation of the this.info object's Author property, which causes the JavaScript engine to maintain references to memory locations that have already been deallocated. This improper memory management creates a window of opportunity for attackers to craft malicious PDF files that can exploit this condition during normal document processing operations.
The operational impact of CVE-2018-3959 extends beyond simple exploitation as it represents a sophisticated attack vector that can be delivered through multiple attack surfaces. The vulnerability can be triggered through traditional file-based attacks where users open malicious PDF documents, but also through web-based attacks when the browser plugin extension is enabled, allowing remote exploitation through web browsers. This dual attack surface significantly increases the attack surface and makes the vulnerability more dangerous as it can be exploited through various delivery mechanisms including phishing emails, compromised websites, or malicious file sharing platforms. The vulnerability's exploitation requires user interaction to open the malicious file or visit the malicious website, but once triggered, it can lead to complete system compromise.
The mitigation strategies for CVE-2018-3959 should focus on immediate remediation through software updates as Foxit Software has released patches to address this specific vulnerability. Organizations should implement strict document handling policies that prevent users from opening untrusted PDF files, particularly those received through email or downloaded from untrusted sources. Network-level protections such as web application firewalls and content filtering solutions should be configured to block suspicious PDF content and monitor for potential exploitation attempts. Additionally, browser security configurations should be hardened by disabling or restricting PDF plugin execution, particularly in environments where users may encounter untrusted content. The vulnerability also highlights the importance of keeping all software components updated, as this type of memory corruption vulnerability typically requires immediate patching to prevent exploitation. Security teams should also implement monitoring for unusual JavaScript engine behavior and memory access patterns that could indicate exploitation attempts, as these vulnerabilities often leave detectable traces in system logs and network traffic.