CVE-2011-4217 in SlimPDF Reader
Summary
by MITRE
Investintech.com SlimPDF Reader does not properly restrict read operations during block data moves, which allows remote attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a crafted PDF document.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/07/2024
The vulnerability identified as CVE-2011-4217 affects Investintech.com SlimPDF Reader, a PDF document viewer application that processes and displays Portable Document Format files. This flaw represents a critical security issue within the application's handling of PDF data structures, specifically during operations involving block data movement. The vulnerability arises from insufficient input validation and improper memory management during the processing of PDF documents, creating a pathway for malicious actors to exploit the application's parsing mechanisms.
The technical flaw manifests in the application's failure to properly restrict read operations when moving block data within PDF documents. During normal PDF processing, applications must carefully manage memory operations when relocating or copying data blocks to ensure data integrity and prevent buffer overflows. In SlimPDF Reader's case, the application does not adequately validate or constrain these operations, allowing attackers to craft specially designed PDF files that trigger unexpected behavior in the memory management system. This improper handling of block data moves creates opportunities for both denial of service conditions and potential code execution.
The operational impact of this vulnerability extends beyond simple application crashes, presenting serious security risks to users who may inadvertently open maliciously crafted PDF documents. Remote attackers can leverage this weakness to cause application instability through denial of service attacks, effectively preventing legitimate users from accessing PDF documents. More concerning is the potential for arbitrary code execution, which could allow attackers to gain control over the victim's system. The vulnerability's remote exploitability means that users need only open a specially crafted PDF file to potentially compromise their systems, making it particularly dangerous in environments where users frequently open documents from untrusted sources.
This vulnerability aligns with several cybersecurity standards and frameworks, including CWE-125, which addresses "Out-of-Bounds Read" conditions in software applications, and CWE-119, which covers "Improper Restriction of Operations within the Bounds of a Memory Buffer." The attack pattern also corresponds to ATT&CK technique T1203, "Exploitation for Client Execution," which describes how adversaries use vulnerabilities in software to execute malicious code on target systems. The flaw demonstrates poor input validation practices that are common in document processing applications, where the complexity of file formats creates numerous potential attack vectors.
Mitigation strategies for this vulnerability should include immediate application updates from Investintech to address the memory management issues in SlimPDF Reader. System administrators should implement strict PDF document filtering policies, particularly for documents received from external sources or untrusted parties. Users should be educated about the risks of opening PDF files from unknown origins, and organizations should consider implementing sandboxing technologies to isolate PDF processing operations. Additionally, network-level controls such as web application firewalls and content filtering solutions can help prevent the delivery of malicious PDF files to end-user systems. Regular security assessments of document processing applications should be conducted to identify similar vulnerabilities in other software components that may pose similar risks to system security and integrity.