CVE-2017-7383 in PoDoFo
Summary
by MITRE
The PdfFontFactory.cpp:195:62 code in PoDoFo 0.9.5 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted PDF document.
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Analysis
by VulDB Data Team • 08/25/2020
The vulnerability identified as CVE-2017-7383 resides within the PoDoFo library version 0.9.5, specifically in the PdfFontFactory.cpp file at line 195. This flaw represents a classic null pointer dereference vulnerability that can be exploited by remote attackers to trigger a denial of service condition. The issue manifests when the library processes a specially crafted PDF document that contains malformed font data, causing the application to crash due to attempting to access a null pointer reference during font processing operations.
This vulnerability falls under the CWE-476 category of NULL Pointer Dereference, which is a well-documented weakness in software systems where applications fail to properly validate pointer values before dereferencing them. The attack vector is particularly concerning as it allows remote exploitation without requiring any authentication or privileged access, making it accessible to any attacker who can deliver a malicious PDF file to a system running vulnerable PoDoFo software. The vulnerability impacts any application that utilizes PoDoFo 0.9.5 for PDF processing, including document viewers, web applications, and server-side PDF generation tools.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged in broader attack scenarios within the MITRE ATT&CK framework under the T1499 category of Network Denial of Service. When exploited, the vulnerability causes applications to crash and terminate unexpectedly, potentially leading to complete service unavailability for users attempting to access PDF documents. This type of denial of service can be particularly damaging in enterprise environments where PDF processing is critical for business operations, or in web applications where such crashes could be amplified through mass exploitation.
Mitigation strategies for CVE-2017-7383 primarily involve upgrading to a patched version of the PoDoFo library, specifically versions 0.9.6 or later where the null pointer dereference has been addressed. Organizations should also implement input validation measures that can detect and reject malformed PDF documents before they reach the vulnerable library components. Additionally, network segmentation and application whitelisting can help limit the potential impact of exploitation attempts, while monitoring systems should be configured to detect unusual application crash patterns that might indicate exploitation attempts. Security teams should also consider implementing sandboxing techniques for PDF processing to contain any potential exploitation attempts and prevent them from affecting the broader system infrastructure.