CVE-2016-4061 in Foxit
Summary
by MITRE
Foxit Reader and PhantomPDF before 7.3.4 on Windows allow remote attackers to cause a denial of service (application crash) via a crafted content stream.
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Analysis
by VulDB Data Team • 10/21/2018
The vulnerability identified as CVE-2016-4061 affects Foxit Reader and PhantomPDF versions prior to 7.3.4 on Windows operating systems, representing a significant security flaw that enables remote attackers to execute denial of service attacks through carefully crafted content streams. This vulnerability resides within the PDF processing components of these applications, specifically in how they handle malformed or maliciously constructed content streams that are part of PDF documents. The flaw manifests when the applications attempt to parse and render content streams that contain unexpected or malformed data structures, leading to application instability and eventual crashes.
The technical implementation of this vulnerability involves the improper handling of content stream data during PDF rendering processes, which falls under the category of input validation and parsing errors. When a maliciously crafted PDF document is opened, the application's content stream parser fails to properly validate the structure and content of the data stream, causing memory corruption or stack overflow conditions that result in application termination. This behavior aligns with CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers buffer overflow vulnerabilities in heap-based memory structures. The vulnerability is particularly concerning because it can be exploited remotely through web-based attacks or malicious email attachments without requiring any special privileges or user interaction beyond opening the malicious document.
The operational impact of this vulnerability extends beyond simple application crashes, as it can be leveraged to disrupt business operations and productivity within organizations that rely on these PDF reading applications. Attackers can craft PDF documents that will cause Foxit Reader or PhantomPDF to crash whenever they are opened, potentially affecting users across different departments including legal, finance, and administrative teams who regularly process PDF documents. The vulnerability's remote exploitation capability means that attackers can deliver malicious payloads through various channels including email, web downloads, or compromised websites, making it particularly dangerous in enterprise environments where PDF documents are frequently shared and processed. This type of attack aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a common vector for disrupting normal business operations through application-level exploits.
Organizations should implement immediate mitigations including updating to Foxit Reader and PhantomPDF version 7.3.4 or later, which contains patches specifically designed to address the content stream parsing vulnerabilities. Network-level protections such as PDF content filtering and sandboxing mechanisms can provide additional defense in depth, while user education regarding suspicious PDF attachments and web downloads can help reduce successful exploitation attempts. Security teams should also consider implementing application whitelisting policies that restrict the execution of unauthorized PDF readers and ensure that only trusted versions of these applications are deployed within the organization. Regular vulnerability assessments and penetration testing should be conducted to identify similar parsing vulnerabilities in other PDF processing applications and ensure comprehensive protection against similar remote denial of service attacks.