CVE-2018-9979 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 Texture Continuation objects in 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 object. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current process. Was ZDI-CAN-5429.
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Analysis
by VulDB Data Team • 02/06/2020
CVE-2018-9979 represents a critical information disclosure vulnerability affecting Foxit Reader version 9.0.0.29935 and potentially other versions within the same release cycle. This vulnerability resides in the Universal 3D file parsing functionality where the application fails to properly validate user-supplied data during the processing of Texture Continuation objects. The flaw manifests as a buffer over-read condition that occurs when the software attempts to parse malformed U3D files containing specially crafted Texture Continuation objects. This type of vulnerability falls under the CWE-125 category of "Out-of-bounds Read" which is classified as a memory safety error that can lead to information disclosure and potentially more severe exploitation vectors. The vulnerability requires user interaction to be successfully exploited, meaning that a victim must either visit a malicious webpage or open a malicious file containing the crafted U3D content.
The technical implementation of this vulnerability involves the parsing of U3D (Universal 3D) files which are used for 3D graphics rendering in various document formats. When Foxit Reader encounters a Texture Continuation object within a U3D file, the application's parser does not adequately validate the object's boundaries or size parameters before attempting to read data from memory locations beyond the allocated buffer space. This improper validation allows an attacker to craft malicious U3D files that cause the parser to read memory contents that should not be accessible to the application. The read past the end of an allocated object creates a scenario where adjacent memory regions containing sensitive information such as stack canaries, heap metadata, or other application data may be inadvertently exposed to the attacker.
From an operational perspective, this vulnerability creates significant risk for organizations that rely on Foxit Reader for document processing and viewing. The attack vector requires social engineering to convince users to open malicious files, making it a medium to high-risk vulnerability in environments where users frequently handle external documents. The information disclosure aspect can reveal sensitive data that might include cryptographic keys, session tokens, or other confidential information stored in memory. Additionally, the vulnerability can serve as a stepping stone for more sophisticated attacks, as the leaked memory information can provide attackers with insights into the application's memory layout and potentially enable them to craft more effective exploit payloads. The ZDI-CAN-5429 reference indicates this vulnerability was tracked by the Zero Day Initiative and was likely part of a coordinated disclosure process.
Organizations should implement immediate mitigations including updating to the latest version of Foxit Reader where this vulnerability has been patched, implementing strict file validation policies for U3D content, and deploying network-based intrusion detection systems that can identify suspicious U3D file patterns. Users should be educated about the risks of opening untrusted documents and the importance of keeping their software updated. The vulnerability's classification under ATT&CK technique T1059.007 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation) suggests that exploitation could potentially lead to privilege escalation if the application runs with elevated privileges. System administrators should also monitor for unusual file access patterns and consider implementing sandboxing mechanisms for document processing to limit the potential impact of successful exploitation attempts.