CVE-2017-10942 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to disclose sensitive information on vulnerable installations of Foxit Reader 8.3.0.14878. 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 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-4737.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-10942 represents a critical information disclosure flaw within Foxit Reader version 8.3.0.14878 that exposes systems to remote exploitation through malicious PDF file manipulation. This vulnerability falls under the category of buffer over-read conditions, which occur when a program attempts to read data beyond the boundaries of allocated memory regions. The flaw specifically manifests during the parsing of PDF files, where the application fails to properly validate user-supplied data before processing it. The lack of adequate input validation creates a scenario where an attacker can craft malicious PDF content that triggers unintended memory access patterns, leading to the disclosure of sensitive information from adjacent memory locations.
The technical implementation of this vulnerability stems from improper bounds checking during PDF file interpretation, particularly when processing certain embedded objects or streams within the document structure. When Foxit Reader encounters malformed or specially crafted PDF elements, the parser does not adequately verify array indices or object sizes before accessing memory regions, resulting in a read past the end of allocated buffers. This memory access violation can expose confidential data such as stack contents, heap metadata, or other sensitive program information that resides adjacent to the targeted memory allocation. The vulnerability is classified as a classic buffer over-read condition, which aligns with CWE-125, a common weakness in software security that represents out-of-bounds read errors.
From an operational perspective, exploitation of this vulnerability requires user interaction through either visiting a malicious web page that hosts the crafted PDF file or opening a malicious document directly. This requirement places the vulnerability in the context of social engineering attacks, where attackers must convince users to interact with compromised content. The attack vector demonstrates the importance of user awareness in security defense, as even well-protected systems can be compromised through human factors. The vulnerability's potential for code execution in combination with other exploits makes it particularly dangerous, as it can serve as a stepping stone for more sophisticated attacks. According to ATT&CK framework, this vulnerability maps to techniques involving initial access through malicious files and privilege escalation through memory corruption exploits.
The impact of this vulnerability extends beyond simple information disclosure, as it creates opportunities for attackers to gather intelligence about the target system's memory layout and application state. This reconnaissance data can significantly aid in developing more advanced exploitation techniques, including bypassing security mechanisms such as address space layout randomization and data execution protection. The vulnerability's exploitation potential increases when combined with other memory corruption issues, as attackers can leverage the information disclosure to craft more precise and effective attacks. Organizations should consider implementing comprehensive security measures including regular software updates, network monitoring for suspicious PDF file activity, and user education programs to mitigate the risk associated with this vulnerability. The ZDI-CAN-4737 reference indicates that this vulnerability was recognized and tracked by the Zero Day Initiative, highlighting its significance in the cybersecurity community and the need for timely remediation.