CVE-2018-5680 in Foxit Reader
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader before 9.1 and PhantomPDF before 9.1. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the processing of specially crafted pdf files with embedded u3d images. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated object. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current process, a different vulnerability than CVE-2018-5677 and CVE-2018-5679.
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Analysis
by VulDB Data Team • 02/08/2020
The vulnerability described in CVE-2018-5680 represents a critical remote code execution flaw affecting Foxit Reader versions prior to 9.1 and PhantomPDF versions before 9.1. This security issue demonstrates the inherent risks associated with PDF processing software and highlights the sophisticated attack vectors that can be exploited through seemingly benign document formats. The vulnerability specifically targets the handling of PDF files containing embedded u3d (Universal 3D) images, which are three-dimensional graphics objects used for complex visualizations and technical drawings within PDF documents. The flaw exists in the software's memory management and data validation mechanisms, creating a pathway for malicious actors to compromise systems through targeted attacks.
The technical root cause of CVE-2018-5680 stems from inadequate input validation during the parsing of u3d embedded content within PDF files. When the vulnerable software processes a specially crafted PDF containing malicious u3d data, it fails to properly validate the boundaries of allocated memory objects. This leads to a read past the end of an allocated buffer, a classic memory corruption vulnerability that can be exploited to overwrite critical memory locations. The vulnerability manifests as a buffer over-read condition where the application attempts to access memory beyond the intended data structure, potentially allowing attackers to manipulate program execution flow. This type of flaw falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions in software applications. The vulnerability is particularly dangerous because it operates at the memory level, allowing for arbitrary code execution within the context of the running application process.
The operational impact of this vulnerability extends beyond simple exploitation, as it creates a persistent threat vector that can be leveraged for advanced persistent threats and privilege escalation attacks. Attackers can craft malicious PDF files that, when opened by an unsuspecting user, automatically trigger the vulnerability without requiring additional user interaction beyond the initial document opening. The attack requires only that the user visit a malicious webpage hosting the exploit or open a crafted PDF file, making it highly effective for phishing campaigns and social engineering attacks. This vulnerability demonstrates the importance of defense in depth strategies, as it can be combined with other exploits to create more sophisticated attack chains. The fact that this vulnerability operates independently from CVE-2018-5677 and CVE-2018-5679 indicates that multiple attack surfaces exist within the same software family, requiring comprehensive patch management strategies. The ATT&CK framework categorizes this vulnerability under the T1059.007 technique, which involves executing malicious code through legitimate system processes, and T1203, which covers exploitation of remote services through malicious file delivery.
Mitigation strategies for CVE-2018-5680 primarily focus on immediate software updates and patch deployment, as the most effective defense against this vulnerability is upgrading to versions 9.1 or later where the issue has been resolved. Organizations should implement comprehensive vulnerability management programs that include regular security assessments of PDF processing applications and their associated dependencies. Network-level defenses such as web application firewalls and content filtering systems can provide additional protection by blocking suspicious PDF content and monitoring for known malicious patterns. Security teams should also consider implementing sandboxing technologies that isolate PDF processing in restricted environments, preventing potential code execution from affecting the primary system. The vulnerability highlights the importance of secure coding practices and input validation, particularly for applications that process complex file formats with embedded multimedia content. Regular security training for end users remains crucial, as the requirement for user interaction makes social engineering attacks particularly effective against this vulnerability. Organizations should also establish incident response procedures specifically designed to handle PDF-based attacks and maintain detailed logs of document access patterns to detect potential exploitation attempts.