CVE-2020-13815 in Foxit
Summary
by MITRE
An issue was discovered in Foxit Reader and PhantomPDF before 9.7.1. It allows stack consumption via a loop of an indirect object reference.
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Analysis
by VulDB Data Team • 10/22/2020
The vulnerability identified as CVE-2020-13815 affects Foxit Reader and PhantomPDF software versions prior to 9.7.1, representing a significant security flaw that could lead to system instability and potential denial of service conditions. This issue manifests through improper handling of object references within PDF documents, specifically involving indirect object references that create infinite loops during parsing operations. The flaw resides in the document processing engine of these PDF readers, where the software fails to properly validate or limit recursive object reference chains that could theoretically continue indefinitely.
The technical implementation of this vulnerability involves a stack consumption mechanism that occurs when the PDF parser encounters a loop of indirect object references. In normal operation, PDF documents contain objects that reference other objects, but when these references form circular dependencies without proper termination conditions, the parsing process can consume excessive stack memory. This type of vulnerability falls under the category of improper input validation and resource exhaustion, with direct implications for memory management within the application's parsing routines. The stack consumption occurs during the interpretation phase of PDF document processing, where each recursive reference consumes additional stack space until system resources are exhausted.
From an operational impact perspective, this vulnerability creates a condition where maliciously crafted PDF documents could be used to trigger denial of service attacks against systems running affected versions of Foxit Reader or PhantomPDF. When a user opens an exploit payload, the application enters an infinite loop consuming system memory and potentially causing application crashes or system instability. This makes the vulnerability particularly dangerous in enterprise environments where these PDF readers are commonly used for document review and processing. The vulnerability can be exploited through social engineering tactics where users are tricked into opening malicious PDF files, making it a prevalent concern for organizations that handle numerous document interactions.
The security implications extend beyond simple denial of service as this vulnerability could potentially be leveraged as a stepping stone for more sophisticated attacks, particularly when combined with other exploitation techniques. Organizations should consider this vulnerability in the context of broader attack surface management strategies, as it represents a weak point in document processing software that could be exploited by threat actors. The flaw demonstrates poor defensive programming practices and inadequate input sanitization, which aligns with common attack patterns documented in the attack tree framework where resource exhaustion serves as a foundational technique for compromising system availability. Mitigation efforts should include immediate patching of affected software versions, implementation of PDF document sanitization policies, and network-level controls to restrict access to potentially malicious documents.
This vulnerability is classified under CWE-400, which addresses "Uncontrolled Resource Consumption," and represents a specific instance of improper resource management within document processing applications. The ATT&CK framework categorizes this under T1499.004, which deals with "Endpoint Denial of Service" techniques, where adversaries leverage resource exhaustion to make systems unavailable. Organizations should implement layered defensive strategies including regular software updates, user education about suspicious document attachments, and monitoring for unusual memory consumption patterns. The vulnerability also highlights the importance of proper software security testing including fuzzing and input validation procedures to prevent similar issues in future software releases.