CVE-2018-3964 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. If the browser plugin extension is enabled, visiting a malicious site can also trigger the vulnerability.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/22/2023
The vulnerability identified as CVE-2018-3964 represents a critical use-after-free flaw within the JavaScript engine of Foxit PDF Reader version 9.1.0.5096, classified under CWE-416 as improper deallocation of memory resources. This vulnerability stems from inadequate memory management practices where the JavaScript engine fails to properly track object references after memory deallocation, creating opportunities for malicious exploitation. The flaw specifically manifests when processing specially crafted PDF documents that contain malformed JavaScript code designed to trigger the use-after-free condition. The vulnerability operates at the intersection of memory corruption and code execution, allowing attackers to manipulate program flow through controlled memory access patterns.
The technical implementation of this vulnerability involves the exploitation of memory management inconsistencies within the PDF reader's JavaScript engine component. When a malicious PDF document is processed, the engine allocates memory for JavaScript objects and subsequently frees them during normal execution flow. However, due to insufficient reference counting or pointer validation mechanisms, the application may attempt to access memory locations that have already been deallocated. This creates a window where attacker-controlled data can be placed in the freed memory space, enabling the reuse of previously freed objects to redirect execution flow or inject malicious code. The vulnerability demonstrates characteristics consistent with heap-based buffer overflows and memory corruption attacks, where the attacker can manipulate the program's execution path through controlled memory layout.
The operational impact of CVE-2018-3964 extends beyond simple privilege escalation to encompass full system compromise when successfully exploited. An attacker requires user interaction to trigger the vulnerability through opening a malicious PDF file, making this a user-initiated attack vector that aligns with social engineering tactics commonly employed in phishing campaigns. The vulnerability's reach is amplified when the browser plugin extension is enabled, as it allows exploitation through web-based delivery methods, expanding the attack surface from file-based to network-based threats. This dual exploitation mechanism significantly increases the attack surface and makes the vulnerability more dangerous in enterprise environments where browser-based PDF viewing is common. The potential for arbitrary code execution means that successful exploitation could result in complete system compromise, data exfiltration, or deployment of persistent malware.
Mitigation strategies for CVE-2018-3964 should prioritize immediate software updates from Foxit Software to address the underlying memory management flaws. System administrators should implement strict document handling policies that restrict PDF file execution and disable unnecessary browser plugins that may expose the system to web-based exploitation. Network-level defenses including web application firewalls and content filtering systems can help detect and block malicious PDF content before it reaches end users. The vulnerability's classification under ATT&CK technique T1203 (Exploitation for Client Execution) highlights the importance of endpoint protection measures and regular security assessments. Organizations should also consider implementing sandboxing mechanisms for PDF processing and establishing incident response procedures specifically designed to handle memory corruption vulnerabilities. Additionally, user education programs should emphasize the dangers of opening untrusted PDF documents and the importance of keeping software up to date with security patches.