CVE-2020-18972 in PoDoFo
Summary
by MITRE • 08/25/2021
Exposure of Sensitive Information to an Unauthorized Actor in PoDoFo v0.9.6 allows attackers to obtain sensitive information via 'IsNextToken' in the component 'src/base/PdfToenizer.cpp'.
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Analysis
by VulDB Data Team • 08/29/2021
The vulnerability identified as CVE-2020-18972 represents a critical information disclosure flaw within the PoDoFo document processing library version 0.9.6. This security weakness manifests through the improper handling of sensitive data during the tokenization process, specifically within the PdfTokenizer.cpp source file. The vulnerability arises from the 'IsNextToken' function which fails to adequately protect sensitive information from being exposed to unauthorized actors during PDF document parsing operations. The flaw demonstrates a classic security oversight where internal processing mechanisms inadvertently leak confidential data to external parties who may not possess proper authorization to access such information.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the PDF tokenization routine. When the PdfTokenizer component processes PDF documents, the 'IsNextToken' function does not properly isolate or protect sensitive data elements that may be present in the document structure. This failure creates an attack vector where malicious actors can exploit the tokenization process to extract information that should remain protected within the application's internal processing context. The vulnerability is particularly concerning because it operates at the parsing layer, meaning that any document processed through this library could potentially expose sensitive information to unauthorized parties. The flaw represents a violation of data confidentiality principles and demonstrates poor separation of concerns within the library's architecture.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable more sophisticated attacks including document reconstruction, metadata extraction, and potential credential harvesting. Attackers leveraging this vulnerability can potentially access sensitive information such as embedded passwords, encryption keys, or other confidential data elements that may be present within PDF documents being processed by affected applications. This exposure can lead to unauthorized access to proprietary information, personal data breaches, or compromise of security-sensitive documents. The vulnerability affects any application that utilizes PoDoFo version 0.9.6 for PDF processing, making it particularly dangerous in enterprise environments where document handling is prevalent.
Security professionals should note this vulnerability aligns with CWE-200, which addresses the exposure of sensitive information to unauthorized actors, and may also relate to CWE-352, concerning cross-site request forgery vulnerabilities in related contexts. From an ATT&CK framework perspective, this vulnerability maps to T1005, Data from Local System, and potentially T1074, Data Staged, as it enables unauthorized access to sensitive information. The remediation strategy should focus on updating to a patched version of PoDoFo, implementing proper input validation in custom applications that utilize this library, and conducting thorough code reviews of tokenization processes. Organizations should also consider implementing network monitoring to detect potential exploitation attempts and establish proper access controls to limit exposure of sensitive documents during processing operations.