CVE-2018-9976 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 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-5425.
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Analysis
by VulDB Data Team • 02/06/2020
The vulnerability identified as CVE-2018-9976 represents a critical information disclosure flaw affecting Foxit Reader version 9.0.0.29935 and potentially other versions within the same product line. This security weakness resides in the software's handling of U3D file formats, specifically within the parsing mechanism for Texture objects. The vulnerability is classified as a buffer over-read condition that occurs when the application processes malformed U3D files containing specially crafted Texture data structures. This issue demonstrates the classic characteristics of a memory safety vulnerability where the application fails to properly validate input boundaries during file processing operations.
The technical exploitation of this vulnerability requires user interaction through either visiting a malicious webpage that loads a crafted U3D file or opening a malicious file directly within the Foxit Reader application. This interaction requirement places the vulnerability in the category of user-initiated attack vectors rather than fully autonomous exploits. The core technical flaw stems from insufficient bounds checking during the parsing of Texture objects within U3D files, where the application attempts to read memory locations beyond the allocated buffer boundaries. This improper validation creates a scenario where an attacker can manipulate the parsing logic to access adjacent memory regions, potentially exposing sensitive data from the application's memory space.
From an operational perspective, the impact of this vulnerability extends beyond simple information disclosure to potentially enable more severe attacks when combined with other exploitation techniques. The read past the end of an allocated object condition creates opportunities for attackers to extract memory contents that may include sensitive information such as encryption keys, session tokens, or other confidential data. The vulnerability's classification as a CWE-125: Out-of-bounds Read aligns with the broader category of memory safety issues that have historically led to privilege escalation and remote code execution attacks. This vulnerability can serve as a stepping stone in multi-stage attack campaigns where attackers first exploit information disclosure to gather intelligence before attempting more sophisticated exploitation techniques.
The security implications of CVE-2018-9976 align with ATT&CK technique T1059.007 for command and scripting interpreter, as the vulnerability can potentially enable attackers to execute code within the application's execution context. The vulnerability's potential for code execution makes it particularly dangerous in environments where Foxit Reader is used for processing untrusted documents. Organizations should consider this vulnerability as part of a broader attack surface that includes document processing applications, where the combination of user interaction requirements and memory safety flaws creates a significant risk profile. The vulnerability's impact is particularly concerning given that Foxit Reader is widely used for viewing and processing PDF documents, making it a common target for adversaries seeking to leverage document-based attack vectors.
Mitigation strategies should focus on immediate patching of affected versions, implementing network-based controls to block access to known malicious U3D files, and establishing user awareness programs to prevent interaction with suspicious content. Organizations should also consider implementing application whitelisting policies that restrict execution of potentially vulnerable applications in high-risk environments. The vulnerability's nature suggests that defensive measures should include monitoring for unusual memory access patterns and implementing strict input validation for all document formats processed by the application. Additionally, regular security assessments of document processing applications should be conducted to identify similar memory safety vulnerabilities that may exist in other components of the software ecosystem.