CVE-2018-3853 in Foxit
Summary
by MITRE
An exploitable use-after-free vulnerability exists in the JavaScript engine of Foxit Software Foxit PDF Reader version 9.0.1.1049. 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.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/21/2023
The vulnerability identified as CVE-2018-3853 represents a critical use-after-free flaw within the JavaScript engine of Foxit PDF Reader version 9.0.1.1049, classified under CWE-416 as use of freed memory. This security weakness enables remote code execution when a malicious PDF document is opened by an unsuspecting user, making it particularly dangerous in enterprise and consumer environments where PDF documents are frequently encountered. The vulnerability stems from improper memory management within the browser plugin extension, which allows attackers to manipulate memory objects that have already been deallocated, creating opportunities for arbitrary code execution.
The technical exploitation of this vulnerability involves crafting a malicious PDF file that triggers a specific sequence of operations within the JavaScript engine. When the vulnerable software processes this crafted document, it executes a use-after-free condition where previously deallocated memory structures are accessed and reused. This flaw occurs during the parsing and execution of JavaScript code embedded within PDF documents, particularly when the browser plugin extension is active. The attacker can leverage this condition to overwrite memory locations with malicious code, potentially gaining full control over the affected system. The vulnerability's exploitation requires user interaction through opening a malicious file or visiting a compromised website when the browser plugin is enabled, making it a prime target for social engineering attacks.
The operational impact of CVE-2018-3853 extends beyond simple code execution to encompass complete system compromise and potential data exfiltration. Attackers can utilize this vulnerability to install persistent backdoors, escalate privileges, or access sensitive information stored on the compromised system. The fact that the vulnerability can be triggered through both file-based and web-based attacks increases its attack surface significantly, as it can be exploited in phishing campaigns, drive-by downloads, or compromised websites. Organizations using Foxit PDF Reader version 9.0.1.1049 face substantial risk of unauthorized access and data breaches, particularly in environments where users regularly handle PDF documents from untrusted sources.
Mitigation strategies for CVE-2018-3853 primarily focus on immediate software updates and operational security measures. The most effective approach involves upgrading to a patched version of Foxit PDF Reader that addresses the memory management issues within the JavaScript engine. Security administrators should also consider implementing browser plugin restrictions and disabling the PDF plugin extension when it is not actively needed. Network-based protections can include content filtering and sandboxing mechanisms that prevent execution of potentially malicious PDF content. Additionally, user education programs should emphasize the importance of avoiding suspicious PDF files and verifying document sources before opening them. Organizations should also monitor for exploitation attempts through intrusion detection systems and implement proper incident response procedures to quickly address any successful compromise attempts. The vulnerability aligns with ATT&CK technique T1059.007 for JavaScript, highlighting the need for comprehensive endpoint protection that monitors for suspicious JavaScript execution patterns within PDF processing environments.