CVE-2018-14293 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Foxit Reader 9.1.0.5096. 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 parsing of PDF documents. By manipulating a document's elements, an attacker can cause a pointer to be reused after it has been freed. An attacker can leverage this vulnerability to execute code under the context of the current process. Was ZDI-CAN-6233.
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Analysis
by VulDB Data Team • 03/11/2020
This vulnerability in Foxit Reader version 9.1.0.5096 represents a critical heap-based buffer overflow condition that stems from improper memory management during PDF document parsing operations. The flaw specifically manifests when the application processes maliciously crafted PDF files containing crafted elements that trigger a use-after-free condition. According to the ZDI-CAN-6233 identifier, this vulnerability operates at the intersection of memory corruption and privilege escalation, where an attacker can manipulate the application's memory allocation patterns to cause a pointer to be dereferenced after it has been freed, creating a dangerous condition that allows arbitrary code execution. The vulnerability's classification aligns with CWE-416 which describes the use of freed memory condition, making it a prime target for exploitation in modern attack frameworks.
The technical exploitation of this vulnerability requires user interaction through either visiting a malicious webpage hosting a crafted PDF or opening a malicious file directly, which means the attack vector follows the typical user-initiated compromise pattern. The PDF parsing engine in Foxit Reader fails to properly validate the memory state of objects during document processing, particularly when handling complex document structures that involve object references and memory deallocation sequences. When an attacker crafts a PDF document with specific element arrangements, the parser's memory management logic causes a pointer to be freed but subsequently accessed, creating a situation where the attacker can control the memory layout and potentially redirect execution flow. This memory corruption vulnerability operates at a fundamental level where the application's heap management fails to maintain proper object lifecycle controls.
The operational impact of this vulnerability extends beyond simple code execution, as it allows attackers to operate under the privileges of the current user context, effectively compromising the entire system if the user has elevated permissions. The attack scenario demonstrates how modern exploit frameworks can leverage such memory corruption vulnerabilities to achieve remote code execution without requiring physical access to the target system. This vulnerability essentially provides an attacker with a foothold that can be escalated to full system compromise, particularly in environments where users have administrative privileges. The fact that exploitation requires user interaction makes this vulnerability suitable for phishing campaigns and social engineering attacks, where the attacker can deliver the malicious PDF through various channels including email attachments, web downloads, or malicious advertisements.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, including immediate patching of affected Foxit Reader installations and network-based intrusion detection systems that can identify malicious PDF content. The ATT&CK framework categorizes this vulnerability under the T1203 - Exploitation for Client Execution technique, where attackers leverage client-side applications to deliver malicious payloads. Organizations should also deploy application whitelisting policies to restrict execution of unsigned or untrusted PDF viewers, and implement strict email filtering to prevent delivery of malicious PDF attachments. Additionally, regular security assessments of document processing applications should be conducted to identify similar memory management issues that may exist in other software components. The vulnerability highlights the critical importance of proper memory management practices in document parsing engines and demonstrates how seemingly benign PDF processing operations can become attack vectors when memory safety is not properly enforced.