CVE-2017-8378 in PoDoFo
Summary
by MITRE
Heap-based buffer overflow in the PdfParser::ReadObjects function in base/PdfParser.cpp in PoDoFo 0.9.5 allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via vectors related to m_offsets.size.
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Analysis
by VulDB Data Team • 08/24/2024
The vulnerability identified as CVE-2017-8378 represents a critical heap-based buffer overflow within the PoDoFo library version 0.9.5, specifically within the PdfParser::ReadObjects function located in base/PdfParser.cpp. This flaw occurs when processing PDF documents and stems from improper handling of the m_offsets.size parameter during object parsing operations. The vulnerability falls under the CWE-121 heap-based buffer overflow category, which is classified as a serious memory safety issue that can lead to arbitrary code execution or system instability.
The technical implementation of this vulnerability exploits the lack of proper bounds checking when the PdfParser processes PDF objects, particularly when the m_offsets.size variable contains an invalid or unexpectedly large value. When attackers craft malicious PDF files with malformed offset structures, the ReadObjects function attempts to allocate heap memory based on these incorrect size parameters, leading to buffer overflow conditions. This type of vulnerability is particularly dangerous in document processing libraries as it can be triggered through normal user interaction with PDF files, making it an attractive target for remote exploitation.
The operational impact of CVE-2017-8378 extends beyond simple denial of service scenarios to potentially enable more severe consequences including application crashes, memory corruption, and in some cases, remote code execution. When applications using PoDoFo process maliciously crafted PDF documents, the buffer overflow can cause the application to terminate unexpectedly or behave unpredictably, effectively creating a denial of service condition that can be exploited by attackers to disrupt services or potentially gain unauthorized system access. The vulnerability is particularly concerning in web applications and document processing services that rely on PoDoFo for PDF handling, as these systems can be targeted through web interfaces.
Mitigation strategies for CVE-2017-8378 should focus on immediate patching of the PoDoFo library to version 0.9.6 or later, which contains the necessary fixes for the buffer overflow condition. Organizations should also implement input validation measures that sanitize PDF file inputs before processing, particularly focusing on offset and size parameters within PDF structures. Network-level defenses including web application firewalls and content filtering systems can help detect and block malicious PDF files before they reach vulnerable applications. Additionally, the vulnerability aligns with ATT&CK technique T1203 (Exploitation for Client Execution) and T1059 (Command and Scripting Interpreter) as it represents a classic buffer overflow attack vector that can be leveraged for privilege escalation and system compromise when combined with other attack vectors. System administrators should also consider implementing application whitelisting policies and regular security assessments to identify and remediate similar vulnerabilities in other PDF processing libraries and document handling components across their infrastructure.