CVE-2018-9950 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 PDF documents. 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-5413.
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Analysis
by VulDB Data Team • 07/14/2024
The vulnerability identified as CVE-2018-9950 represents a critical information disclosure flaw affecting Foxit Reader version 9.0.0.29935 and potentially other versions within the same release cycle. This vulnerability operates at the core of PDF document parsing functionality, specifically targeting the manner in which the application processes user-supplied data within PDF files. The flaw manifests when the software fails to properly validate input parameters during PDF document parsing, creating a condition where memory access occurs beyond the boundaries of allocated objects. This type of vulnerability falls under the category of buffer over-read conditions as classified by CWE-126, which directly relates to improper validation of user-supplied data. The security implications extend beyond simple information disclosure, as this vulnerability can serve as a foundational element for more sophisticated attacks.
The technical exploitation of this vulnerability requires user interaction through either visiting a malicious webpage or opening a specially crafted malicious PDF file. This requirement places the vulnerability within the realm of social engineering attacks, where the attacker must convince a user to interact with the malicious content. The attack vector operates through the PDF parsing engine of Foxit Reader, where malformed or specially constructed PDF elements trigger the buffer over-read condition. When the application attempts to process these malformed elements, it accesses memory locations beyond the intended data boundaries, potentially exposing sensitive information from adjacent memory regions. This memory access pattern can reveal system information, application state data, or even partial contents of other memory segments that may contain credentials or other sensitive material.
The operational impact of this vulnerability extends significantly beyond simple data exposure, as it creates opportunities for more severe exploitation techniques. An attacker leveraging this vulnerability can potentially use the information disclosure as a stepping stone for additional attacks, including privilege escalation or code execution within the application context. The vulnerability's classification aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the disclosed information could be used to craft more targeted attacks against the system. When combined with other vulnerabilities present in the same application or system environment, this information disclosure can enable attackers to gain deeper insights into system memory layouts, application structures, and potential security weaknesses that could lead to complete system compromise. The vulnerability's presence in the parsing layer makes it particularly dangerous as it affects the core functionality that users rely on for document processing.
Mitigation strategies for CVE-2018-9950 should focus on immediate remediation through software updates provided by Foxit Corporation, as well as implementing defensive measures to reduce the attack surface. Organizations should deploy the latest patches and updates immediately upon availability, as these typically contain specific fixes for the buffer over-read condition in PDF parsing. Network-based defenses should include web application firewalls and content filtering systems that can detect and block malicious PDF content before it reaches end users. Additionally, implementing user education programs to raise awareness about the dangers of opening unknown or untrusted PDF files can significantly reduce successful exploitation attempts. Security monitoring should include detection of unusual memory access patterns and information disclosure events that could indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and boundary checking in security-critical applications, aligning with security best practices outlined in the OWASP Top Ten and NIST cybersecurity frameworks. Regular vulnerability assessments and penetration testing should be conducted to identify similar issues in other software components that process user-supplied data.