CVE-2018-17688 in PhantomPDF
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit PhantomPDF 9.2.0.9297. 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 handling of the setItems method of a ComboBox. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-7069.
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Analysis
by VulDB Data Team • 08/01/2024
CVE-2018-17688 represents a critical remote code execution vulnerability affecting Foxit PhantomPDF version 9.2.0.9297, classified under CWE-476 as a null pointer dereference vulnerability. This flaw exists within the ComboBox component's setItems method where the application fails to validate whether an object reference exists before attempting to perform operations on it. The vulnerability stems from inadequate input validation and object lifecycle management within the PDF rendering engine, creating a dangerous condition where maliciously crafted PDF files can trigger unauthorized code execution. The attack requires user interaction through visiting a malicious webpage or opening a compromised PDF document, making it particularly dangerous in phishing campaigns and targeted attacks.
The technical exploitation of this vulnerability occurs when a malicious PDF document contains specially crafted ComboBox elements that manipulate the setItems method in unexpected ways. When the vulnerable PDF reader processes these elements, it attempts to access a null or improperly initialized object reference, leading to a crash or potentially allowing an attacker to inject and execute arbitrary code within the context of the current process. This type of vulnerability falls under the ATT&CK technique T1203 - Exploitation for Client Execution, where adversaries leverage application vulnerabilities to execute malicious code on targeted systems. The vulnerability's impact is significant as it allows attackers to bypass standard security controls and execute commands with the privileges of the affected user.
The operational implications of CVE-2018-17688 extend beyond simple exploitation, as it represents a fundamental flaw in the PDF processing engine's object management and memory handling capabilities. Organizations using Foxit PhantomPDF 9.2.0.9297 face substantial risk from this vulnerability, particularly in environments where users regularly open PDF documents from untrusted sources. The vulnerability's remote nature means that attackers can deliver malicious payloads through various vectors including email attachments, web downloads, and compromised websites, making it difficult to defend against without proper patching. Security teams must understand that this vulnerability can be leveraged for privilege escalation, data exfiltration, and establishment of persistent access points within targeted networks, particularly in enterprise environments where PDF readers are widely deployed.
Mitigation strategies for CVE-2018-17688 should prioritize immediate patching of affected Foxit PhantomPDF installations, with vendors releasing updates that properly validate object references before operations are performed. Organizations should implement network-based protections including web proxies that scan PDF content for malicious elements and deploy email filtering solutions that block suspicious PDF attachments. Additional defensive measures include user education programs to reduce the likelihood of visiting malicious websites or opening compromised files, along with application whitelisting policies that restrict PDF reader execution to trusted environments. The vulnerability demonstrates the importance of proper input validation and object lifecycle management in security-critical applications, aligning with industry best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework. Organizations should also consider implementing runtime application self-protection (RASP) solutions that can detect and prevent exploitation attempts in real-time, providing additional defense layers against this and similar vulnerabilities.