CVE-2009-3431 in Acrobat
Summary
by MITRE
Stack consumption vulnerability in Adobe Reader and Acrobat 9.1.3, 9.1.2, 9.1.1, and earlier 9.x versions; 8.1.6 and earlier 8.x versions; and possibly 7.1.4 and earlier 7.x versions allows remote attackers to cause a denial of service (application crash) via a PDF file with a large number of [ (open square bracket) characters in the argument to the alert method. NOTE: some of these details are obtained from third party information.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/14/2025
This vulnerability represents a classic stack consumption flaw that affects multiple versions of Adobe Reader and Acrobat software across different release series. The issue manifests when processing specially crafted PDF files containing an excessive number of opening square bracket characters within the argument of the alert method. The vulnerability falls under the category of denial of service attacks that specifically target application stability through resource exhaustion. The flaw exploits the way these applications handle input validation and memory allocation during PDF parsing operations, particularly when encountering malformed or excessively formatted alert commands.
The technical implementation of this vulnerability involves the exploitation of insufficient input sanitization within the PDF processing engine. When Adobe Reader or Acrobat encounters a PDF file containing an excessive number of opening square brackets in the alert method argument, the application's stack memory management becomes overwhelmed. This occurs because the parsing routine does not properly validate the length or complexity of input parameters, leading to uncontrolled stack growth. The vulnerability is particularly dangerous because it can be triggered remotely through malicious PDF files delivered via email attachments, web downloads, or malicious websites. The attack vector leverages the standard alert method functionality that is commonly used in PDF documents for user notifications, making the exploit both subtle and widespread in potential impact.
From an operational perspective, this vulnerability creates significant risk for organizations relying on Adobe Reader and Acrobat for document processing and viewing. The denial of service condition results in application crashes that can disrupt workflow and productivity, potentially requiring system restarts to restore normal operation. The impact extends beyond simple inconvenience as users may lose unsaved work and face interruptions during critical document review processes. Security teams must consider this vulnerability as part of their broader threat landscape, particularly in environments where PDF files are frequently exchanged and processed. The vulnerability's presence across multiple software versions including 7.x, 8.x, and 9.x releases means that organizations must carefully assess their software inventory and patch management processes to ensure complete coverage.
The vulnerability can be mapped to CWE-400, which specifically addresses "Uncontrolled Resource Consumption," and potentially to CWE-129, "Improper Validation of Array Index," as the issue involves improper handling of input parameters that exceed expected bounds. In terms of the MITRE ATT&CK framework, this vulnerability aligns with T1499.004, "Endpoint Denial of Service," and T1203, "Exploitation for Client Execution," as it enables adversaries to cause service disruption and potentially execute malicious code through PDF-based attacks. Organizations should implement multiple layers of defense including regular patching, PDF file scanning, network-based intrusion detection systems, and user education about suspicious email attachments. The vulnerability highlights the importance of proper input validation and resource management in software development, particularly for applications that process untrusted data from external sources. Security professionals should also consider implementing sandboxing solutions and content filtering mechanisms to prevent exploitation of such vulnerabilities in production environments.