CVE-2017-10943 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-4738.
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Analysis
by VulDB Data Team • 01/21/2021
The vulnerability identified as CVE-2017-10943 represents a critical information disclosure flaw affecting Foxit Reader version 8.3.0.14878 and potentially other versions within the same product line. This vulnerability operates at the intersection of memory safety and input validation, creating a pathway for remote attackers to access sensitive system information. The flaw manifests specifically during the processing of PDF documents, making it particularly dangerous given the widespread use of PDF files across enterprise and individual environments. The vulnerability's classification aligns with CWE-125, which describes out-of-bounds read conditions that occur when software reads data beyond the boundaries of allocated memory regions.
The technical implementation of this vulnerability stems from inadequate validation mechanisms within Foxit Reader's PDF parsing engine. When processing maliciously crafted PDF files, the application fails to properly validate user-supplied data during the parsing phase, leading to a buffer over-read condition. This memory safety issue allows an attacker to read data from memory locations beyond the intended boundaries of allocated objects, potentially exposing sensitive information such as stack contents, heap data, or other process memory segments. The read past the end of an allocated object condition creates a scenario where adjacent memory regions containing confidential data become accessible to unauthorized parties. This type of vulnerability is particularly concerning because it can be leveraged as a stepping stone for more sophisticated attacks, including privilege escalation and code execution.
The operational impact of CVE-2017-10943 extends beyond simple information disclosure, as it provides attackers with valuable reconnaissance data that can be used to craft more targeted attacks. The requirement for user interaction through visiting malicious web pages or opening compromised files means that social engineering remains a critical component of exploitation strategies. However, the vulnerability's remote nature and the widespread use of Foxit Reader make it an attractive target for cybercriminals. Attackers can leverage this vulnerability to gather system information, identify running processes, and potentially discover other system weaknesses that could be exploited in subsequent attack phases. The vulnerability's presence in a widely deployed PDF reader creates a significant risk for organizations that rely on document processing capabilities, as it can be triggered through legitimate business activities such as email attachments or web-based document viewing.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security enhancements. The primary recommendation involves updating to the latest version of Foxit Reader where the vulnerability has been patched, as this directly addresses the underlying parsing logic that enables the out-of-bounds read condition. Organizations should also implement network-based security controls such as web application firewalls and content filtering systems that can detect and block malicious PDF files before they reach end users. Additionally, security awareness training programs should emphasize the dangers of opening unexpected email attachments or visiting untrusted websites that may host malicious PDF content. From an ATT&CK framework perspective, this vulnerability maps to techniques involving initial access through malicious files and privilege escalation through information gathering, making it a critical component in the threat landscape for organizations using vulnerable PDF readers. The vulnerability's characteristics align with defensive measures that focus on input validation, memory safety, and application sandboxing to prevent similar issues from compromising system integrity.