CVE-2018-19059 in Poppler
Summary
by MITRE
An issue was discovered in Poppler 0.71.0. There is a out-of-bounds read in EmbFile::save2 in FileSpec.cc, will lead to denial of service, as demonstrated by utils/pdfdetach.cc not validating embedded files before save attempts.
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Analysis
by VulDB Data Team • 06/05/2023
The vulnerability identified as CVE-2018-19059 represents a critical out-of-bounds read flaw within the Poppler PDF rendering library version 0.71.0. This issue manifests in the EmbFile::save2 method located within the FileSpec.cc source file, demonstrating a classic buffer overread condition that can be exploited to cause system instability. The vulnerability specifically affects the pdfdetach utility which is part of the Poppler suite of PDF tools designed for extracting embedded files from PDF documents. When the utility attempts to process embedded files without proper validation, it triggers the out-of-bounds memory access that leads to denial of service conditions.
The technical nature of this vulnerability aligns with CWE-125, which describes out-of-bounds read conditions where programs access memory locations beyond the boundaries of allocated buffers. This flaw occurs because the EmbFile::save2 function fails to validate the size and bounds of embedded file data before attempting to save it to disk. The vulnerability is particularly concerning as it operates at the file processing level where arbitrary PDF content can be fed to the utility, making it susceptible to exploitation through crafted malicious PDF files. The out-of-bounds read can cause the pdfdetach utility to crash or behave unpredictably, effectively rendering the tool unusable for legitimate file extraction operations.
From an operational impact perspective, this vulnerability creates significant denial of service risks for systems that rely on Poppler utilities for PDF processing, particularly in environments where automated PDF handling is common. The flaw can be exploited by attackers who craft malicious PDF files containing malformed embedded objects, causing legitimate pdfdetach operations to fail and potentially disrupting document processing workflows. Systems that depend on automated PDF analysis or extraction capabilities may experience complete service interruptions when encountering vulnerable PDF files, making this a particularly dangerous issue for enterprise document management systems, web applications processing PDF uploads, and any infrastructure relying on Poppler for PDF manipulation tasks.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1203, which involves the use of malicious files to cause system instability and denial of service conditions. Organizations should implement immediate mitigations including updating to Poppler versions that contain the fix for this vulnerability, as well as deploying input validation measures that prevent processing of untrusted PDF files. Additionally, system administrators should consider implementing sandboxing techniques when processing PDF content and monitor for unusual pdfdetach utility behavior that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper bounds checking in file processing utilities and highlights the need for comprehensive input validation across all PDF parsing components to prevent similar issues from occurring in other parts of the Poppler library or similar PDF processing frameworks.