CVE-2019-10871 in Poppler
Summary
by MITRE
An issue was discovered in Poppler 0.74.0. There is a heap-based buffer over-read in the function PSOutputDev::checkPageSlice at PSOutputDev.cc.
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Analysis
by VulDB Data Team • 08/27/2023
The vulnerability identified as CVE-2019-10871 represents a critical heap-based buffer over-read flaw within the Poppler PDF rendering library version 0.74.0. This issue resides in the PSOutputDev::checkPageSlice function located in the PSOutputDev.cc source file, making it a significant security concern for any system that processes PDF documents through this library. The vulnerability stems from improper bounds checking during the processing of PostScript output generation, where the application fails to validate the size of data being read from heap memory before accessing it. Such buffer over-read conditions typically occur when an application attempts to read data beyond the allocated memory boundaries, potentially exposing sensitive information or enabling further exploitation.
The technical implementation of this vulnerability involves the PSOutputDev::checkPageSlice function which handles page slice checking operations during PostScript output generation from PDF documents. When processing malformed or specially crafted PDF files, the function does not adequately validate input parameters or memory boundaries, leading to a situation where heap memory locations beyond the intended buffer limits are accessed. This over-read behavior can result in information disclosure, as the application may read and potentially expose data from adjacent memory regions that contain sensitive information such as stack contents, heap metadata, or other process memory segments. The vulnerability falls under CWE-125, which specifically addresses out-of-bounds read conditions, and aligns with ATT&CK technique T1059.007 for execution through scripting languages and T1550.002 for use of valid accounts, as exploitation may require valid PDF file processing capabilities.
The operational impact of CVE-2019-10871 extends beyond simple information disclosure, as it creates potential pathways for more sophisticated attacks within systems that rely on Poppler for PDF processing. Systems utilizing this library for document conversion, previewing, or rendering operations become vulnerable to attackers who can craft malicious PDF files to trigger the buffer over-read condition. This vulnerability affects a wide range of applications including web browsers, document viewers, and server-side PDF processing services that depend on Poppler. The exploitation scenario typically requires an attacker to deliver a malicious PDF file to a victim system where the vulnerable library is in use, making it particularly concerning for email servers, web applications, and document management systems. Organizations using Poppler 0.74.0 or earlier versions face significant risk, as the vulnerability can be leveraged to extract sensitive information from memory or potentially facilitate further exploitation through information leakage that might aid in bypassing security mechanisms.
Mitigation strategies for CVE-2019-10871 primarily focus on immediate version upgrades to Poppler 0.75.0 or later, which contain the necessary patches to address the buffer over-read condition. System administrators should prioritize updating their Poppler installations and verify that all dependent applications have been updated accordingly. Additionally, implementing input validation measures and sandboxing techniques can provide additional protection layers, though these are considered temporary mitigations until the official patch is applied. Organizations should also monitor their systems for potential exploitation attempts through anomalous PDF processing activities and implement network-based intrusion detection systems that can identify suspicious PDF file transfers. The vulnerability demonstrates the importance of maintaining up-to-date software libraries and implementing comprehensive security testing procedures for third-party components, particularly those handling untrusted input data such as PDF documents. Regular security audits and vulnerability assessments should include checks for outdated library versions to prevent similar issues from compromising system security.