CVE-2011-4218 in SlimPDF Reader
Summary
by MITRE
Investintech.com SlimPDF Reader does not prevent faulting-instruction data from affecting write operations, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted PDF document.
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Analysis
by VulDB Data Team • 12/02/2024
The vulnerability identified as CVE-2011-4218 affects Investintech.com SlimPDF Reader, a PDF document viewing application that fails to properly handle memory access patterns during fault conditions. This flaw represents a classic buffer overflow scenario where the application does not adequately validate or sanitize data that may be processed during memory fault operations, creating a dangerous condition where maliciously crafted PDF content can trigger unexpected behavior in the application's memory management subsystem.
The technical implementation of this vulnerability stems from improper handling of memory faulting instructions within the PDF parsing mechanism. When SlimPDF Reader encounters malformed PDF data structures, the application's memory management routines fail to properly isolate fault conditions from subsequent write operations. This creates a scenario where data that should remain isolated during error handling can influence memory write operations, leading to unpredictable behavior that can be exploited by remote attackers. The vulnerability specifically manifests when the application attempts to process corrupted or specially crafted PDF files that trigger memory fault conditions during document rendering.
From an operational perspective, this vulnerability presents significant risk to organizations that rely on SlimPDF Reader for document processing, as it can be exploited remotely through malicious PDF files delivered via email attachments, web downloads, or other attack vectors. The impact ranges from complete application crashes that result in denial of service conditions to potential code execution capabilities that could allow attackers to run arbitrary commands on affected systems. The remote exploitability means that attackers do not require physical access to target systems, making this vulnerability particularly dangerous in enterprise environments where PDF documents are frequently shared and opened.
The vulnerability aligns with CWE-125, which describes out-of-bounds read conditions, and CWE-787, which covers out-of-bounds write conditions, both of which are fundamental memory safety issues that have been extensively documented in the cybersecurity community. Additionally, this vulnerability maps to ATT&CK technique T1203, which involves exploitation of remote services through malicious file delivery, and T1059, which covers the execution of malicious code through compromised applications. Organizations should consider implementing network-based intrusion detection systems to monitor for suspicious PDF file transfers and ensure that all PDF readers are regularly updated with security patches.
Mitigation strategies should include immediate patching of affected SlimPDF Reader versions, implementation of PDF file validation controls, and network segmentation to limit exposure to potentially malicious PDF content. Organizations should also consider deploying application whitelisting solutions to restrict execution of unauthorized PDF readers, and implement email filtering solutions that can detect and quarantine suspicious PDF attachments. The most effective long-term solution involves upgrading to modern PDF processing libraries that have robust memory safety mechanisms and regular security updates. Security teams should also conduct regular vulnerability assessments to identify similar flaws in other PDF processing applications and ensure that all document handling systems maintain proper input validation and memory management practices.