CVE-2018-17622 in Foxit
Summary
by MITRE
This vulnerability allows remote attackers to disclose sensitive information on vulnerable installations of Foxit Reader 9.1.0.5096. 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 handling of Calculate events. 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 buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-6354.
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Analysis
by VulDB Data Team • 04/07/2020
The vulnerability identified as CVE-2018-17622 represents a critical buffer over-read condition affecting Foxit Reader version 9.1.0.5096, classified under CWE-125 as an out-of-bounds read error. This flaw manifests within the application's handling of Calculate events, which are typically triggered during PDF document processing when mathematical expressions or formulas need evaluation. The vulnerability stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data before processing, creating an exploitable condition where maliciously crafted PDF content can cause the application to read memory beyond allocated buffer boundaries. The security implications are severe as this vulnerability enables attackers to potentially access sensitive information stored in adjacent memory locations, including potentially sensitive data, credentials, or application state information that could be leveraged for further exploitation.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a potential code execution vector that aligns with ATT&CK technique T1059.007 for command and scripting interpreter usage. When a user visits a malicious webpage hosting a crafted PDF file or opens a specially constructed document, the vulnerable Calculate event processing triggers the buffer over-read condition. This allows attackers to potentially execute arbitrary code within the context of the Foxit Reader process, effectively providing a path to compromise the victim's system. The requirement for user interaction makes this vulnerability more challenging to exploit at scale but does not eliminate its threat potential, particularly in targeted attacks where social engineering can be employed to deliver malicious content.
Mitigation strategies for CVE-2018-17622 should focus on immediate remediation through official vendor patches, as Foxit released updates addressing this specific vulnerability in subsequent versions of their software. Organizations should implement strict PDF document filtering and validation policies, particularly for documents received from untrusted sources or external entities. Network-level defenses can include PDF content inspection tools that can detect and block known malicious patterns, though these solutions may not prevent exploitation of this specific buffer over-read condition. Security monitoring should include detection of unusual memory access patterns or potential exploitation attempts, with particular attention to processes exhibiting abnormal behavior when handling PDF documents. The vulnerability demonstrates the importance of robust input validation and proper memory management practices in client-side applications, aligning with security best practices outlined in the OWASP Top Ten and NIST Cybersecurity Framework. System administrators should also consider implementing user education programs to raise awareness about the risks of opening untrusted PDF documents and the importance of keeping software updated to protect against known vulnerabilities.