CVE-2017-8054 in PoDoFo
Summary
by MITRE
The function PdfPagesTree::GetPageNodeFromArray in PdfPageTree.cpp:464 in PoDoFo 0.9.5 allows remote attackers to cause a denial of service (infinite recursion and application crash) via a crafted PDF document.
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Analysis
by VulDB Data Team • 09/19/2020
The vulnerability identified as CVE-2017-8054 resides within the PoDoFo library version 0.9.5, specifically in the PdfPagesTree::GetPageNodeFromArray function located in PdfPageTree.cpp at line 464. This flaw represents a critical security issue that enables remote attackers to execute denial of service attacks against applications utilizing the library. The vulnerability stems from inadequate input validation and recursive call handling within the PDF page tree processing logic, creating a scenario where malformed PDF documents can trigger infinite recursion patterns that ultimately lead to application crashes and system instability.
The technical implementation of this vulnerability exploits the recursive nature of PDF page tree structures where the GetPageNodeFromArray function fails to properly validate the depth or structure of page node arrays during processing. When a crafted PDF document contains maliciously constructed page tree references or circular dependencies, the function enters an infinite recursion loop that consumes system resources and eventually causes the application to crash. This behavior aligns with CWE-674, which categorizes "Uncontrolled Recursion" as a weakness where recursive functions lack proper termination conditions or input validation. The recursive nature of the vulnerability means that even a single malicious page reference can cause the entire application to become unresponsive, making it particularly dangerous in server environments where multiple concurrent requests might be processed.
From an operational perspective, this vulnerability poses significant risks to organizations that rely on PoDoFo for PDF processing, including document management systems, web applications, and content management platforms. The impact extends beyond simple service disruption as the infinite recursion can consume excessive CPU cycles and memory resources, potentially leading to system resource exhaustion and affecting other running processes. Applications using PoDoFo may experience complete service unavailability when processing malicious PDF files, which could result in business interruption and potential data loss. The vulnerability's remote exploitability means that attackers can trigger the denial of service condition without requiring physical access to the target system, making it particularly attractive for attackers seeking to disrupt services.
The mitigation strategies for CVE-2017-8054 primarily focus on immediate library updates and implementation of defensive programming practices. Organizations should prioritize upgrading to PoDoFo versions that contain fixes for this vulnerability, typically released in subsequent versions after 0.9.5. Additionally, implementing proper input validation and recursion depth limiting mechanisms within applications that process PDF documents can provide additional protection layers. Security practitioners should consider deploying PDF processing gateways or sandboxing mechanisms that can detect and prevent malicious PDF content from reaching the core application. The vulnerability also highlights the importance of following ATT&CK framework tactics such as T1499.004 for Network Denial of Service, where adversaries leverage software vulnerabilities to disrupt services. Organizations should implement monitoring and logging of PDF processing activities to detect anomalous behavior patterns that might indicate exploitation attempts, ensuring comprehensive defense in depth strategies are maintained.