CVE-2018-9978 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 object. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the context process. Was ZDI-CAN-5428.
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Analysis
by VulDB Data Team • 02/06/2020
CVE-2018-9978 represents a critical information disclosure vulnerability affecting Foxit Reader version 9.0.0.29935 and potentially other versions within the same product line. This vulnerability falls under the CWE-125 weakness category, which specifically addresses out-of-bounds read conditions where an application attempts to read data beyond the boundaries of allocated memory regions. The flaw manifests during the processing of Universal 3D (U3D) files, which are three-dimensional graphics formats commonly used for embedding 3D content within PDF documents. The vulnerability stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data during the parsing process, creating a dangerous scenario where maliciously crafted U3D files can trigger memory access violations.
The technical exploitation of this vulnerability requires user interaction, meaning that victims must either navigate to a malicious web page hosting compromised U3D content or open a specially crafted PDF file containing malicious U3D elements. This requirement places the vulnerability in the context of social engineering attacks, where attackers must convince users to interact with malicious content. The specific memory corruption occurs when the Foxit Reader application attempts to parse U3D files without adequate bounds checking, leading to a read past the end of an allocated object. This memory access violation creates a potential information disclosure scenario where attackers can extract sensitive data from adjacent memory regions, potentially including credentials, session tokens, or other confidential information stored in the application's memory space.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with a foundation for more sophisticated attacks. According to ATT&CK framework category T1059.007 for command and scripting interpreter, this vulnerability can serve as a precursor for code execution attacks when combined with other exploitation techniques. The out-of-bounds read condition creates memory corruption that can be leveraged to manipulate program execution flow, potentially leading to arbitrary code execution within the context of the Foxit Reader process. This represents a significant escalation from the initial information disclosure, as attackers can use the memory corruption to inject and execute malicious code, effectively compromising the user's system. The vulnerability's exploitation requires careful crafting of malicious U3D files that can trigger the specific memory access pattern, making it a targeted attack vector rather than a widespread exploit.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, including immediate patching of affected Foxit Reader installations to version 9.0.1.30031 or later, which contains the necessary fixes for the U3D parsing routine. Network-based defenses should include content filtering solutions that can detect and block suspicious U3D file content, particularly when embedded within PDF documents. Additionally, user education programs should emphasize the importance of avoiding untrusted PDF files and web content, as this vulnerability relies heavily on social engineering for successful exploitation. The vulnerability demonstrates the importance of proper input validation and bounds checking in document processing applications, as highlighted by CWE-125 requirements for robust memory access controls. Organizations should also consider implementing application whitelisting policies that restrict the execution of potentially vulnerable applications, and establish monitoring procedures to detect unusual memory access patterns that might indicate exploitation attempts.