CVE-2018-9983 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to disclose sensitive information on vulnerable installations of Foxit Reader 9.0.0.29935. 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 U3D files. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the context process. Was ZDI-CAN-5494.
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Analysis
by VulDB Data Team • 02/06/2020
The vulnerability identified as CVE-2018-9983 represents a critical information disclosure flaw within Foxit Reader version 9.0.0.29935 that exposes systems to remote exploitation. This vulnerability specifically targets the Universal 3D (U3D) file parsing functionality, which is commonly used for rendering 3D graphics within PDF documents. The flaw manifests when the application processes malformed U3D files without adequate input validation, creating a condition where memory access violations can occur. According to the ZDI-CAN-5494 reference, this vulnerability was independently identified and documented by the Zero Day Initiative, highlighting its significance in the cybersecurity landscape. The vulnerability requires user interaction to be exploited, meaning that an attacker must convince a victim to visit a malicious webpage or open a compromised file containing the malicious U3D content.
The technical implementation of this vulnerability stems from improper handling of user-supplied data during U3D file processing, which directly maps to CWE-125, known as "Out-of-Bounds Read." When Foxit Reader encounters a crafted U3D file, the application fails to properly validate the structure and boundaries of the data, leading to a situation where the parser attempts to read memory locations beyond the allocated buffer. This out-of-bounds memory access can result in the disclosure of sensitive information from adjacent memory regions, potentially including stack contents, heap data, or other process memory segments. The vulnerability's exploitation requires a specific attack vector involving crafted U3D content that manipulates the parser's internal state, causing it to traverse memory beyond intended boundaries. The lack of proper bounds checking and input sanitization creates an exploitable condition that can be leveraged by attackers to gain insights into the application's memory layout and potentially extract confidential data.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can serve as a precursor to more serious exploitation techniques. Attackers can use the information disclosed through this vulnerability to understand the memory layout of the Foxit Reader process, which can then be combined with other vulnerabilities to achieve remote code execution. This chaining capability makes CVE-2018-9983 particularly dangerous in targeted attack scenarios where adversaries seek to establish persistent access to systems. The vulnerability affects organizations that rely heavily on PDF document processing, particularly those that may not regularly update their software or may have legacy systems running vulnerable versions of Foxit Reader. The requirement for user interaction means that social engineering remains a critical attack vector, as attackers must craft convincing phishing campaigns or malicious websites to deliver the exploit. Organizations using Foxit Reader for document review and collaboration are particularly at risk since the software is commonly used in environments where users frequently open documents from external sources.
Mitigation strategies for CVE-2018-9983 should prioritize immediate software updates to the latest version of Foxit Reader that addresses this vulnerability. System administrators should implement strict document filtering policies that prevent the automatic execution of embedded 3D content or U3D files within PDF documents. Network-based security controls such as web application firewalls and content filtering solutions can help detect and block malicious U3D content before it reaches end-user systems. Additionally, user education programs should emphasize the importance of avoiding suspicious websites and untrusted PDF documents, particularly those containing embedded multimedia content. Organizations should also consider implementing sandboxing techniques for PDF processing, which can isolate the vulnerable application from critical system resources. The ATT&CK framework categorizes this vulnerability under T1203, "Exploitation for Client Execution," as it involves leveraging software vulnerabilities to execute malicious code through user interaction. Regular security assessments and vulnerability scanning should include checks for outdated Foxit Reader installations, while incident response procedures should account for potential exploitation of this vulnerability in the event of a security breach.