CVE-2018-3945 in Foxit
Summary
by MITRE
An exploitable use-after-free vulnerability exists in the JavaScript engine of Foxit Software's Foxit PDF Reader version 9.1.0.5096. A specially crafted PDF document can trigger a previously freed object in memory to be reused, resulting in arbitrary code execution. An attacker needs to trick the user to open the malicious file to trigger this vulnerability.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 07/30/2024
The vulnerability identified as CVE-2018-3945 represents a critical use-after-free flaw within the JavaScript engine of Foxit PDF Reader version 9.1.0.5096. This type of vulnerability falls under the Common Weakness Enumeration category CWE-416, which specifically addresses the use of freed memory conditions that can lead to unpredictable behavior and potential exploitation. The flaw manifests when the JavaScript engine processes specially crafted PDF documents that contain malicious code designed to manipulate memory allocation and deallocation patterns.
The technical implementation of this vulnerability occurs through the improper handling of memory objects within the PDF reader's JavaScript interpreter. When processing a malicious PDF file, the engine allocates memory for certain objects and subsequently frees them during normal execution flow. However, the flawed implementation allows for a scenario where the application attempts to access or reuse these previously freed memory locations before proper garbage collection occurs. This creates a window of opportunity for attackers to manipulate the freed memory contents and redirect execution flow to malicious code.
The operational impact of this vulnerability extends beyond simple code execution, as it represents a complete compromise of the target system. An attacker who successfully exploits this vulnerability can execute arbitrary code with the privileges of the user running the PDF reader, potentially leading to full system compromise. The attack vector requires social engineering to trick users into opening the malicious PDF file, making it particularly dangerous in enterprise environments where users may inadvertently encounter such documents through email attachments or web downloads. This vulnerability directly aligns with ATT&CK technique T1059.007 for Windows Scripting and T1203 for Exploitation for Client Execution, demonstrating the multi-layered attack approach required for successful exploitation.
Mitigation strategies for CVE-2018-3945 should focus on immediate remediation through official software updates provided by Foxit Software, as the vendor has released patches addressing this specific use-after-free condition. Organizations should implement strict document filtering policies that prevent users from opening PDF files from untrusted sources, combined with regular security awareness training to reduce social engineering success rates. Network-based protections such as sandboxing PDF processing and implementing content inspection solutions can provide additional layers of defense. The vulnerability also highlights the importance of keeping all PDF reader software updated and following secure coding practices that prevent improper memory management. System administrators should monitor for exploitation attempts through network traffic analysis and implement endpoint protection solutions that can detect anomalous behavior patterns associated with memory corruption exploits. Given the nature of this vulnerability, organizations should also consider implementing privileged access controls and regular security assessments to identify potential attack vectors and ensure comprehensive protection against similar memory corruption vulnerabilities.