CVE-2007-0046 in Acrobat Reader Plugin
Summary
by MITRE
Double free vulnerability in the Adobe Acrobat Reader Plugin before 8.0.0, as used in Mozilla Firefox 1.5.0.7, allows remote attackers to execute arbitrary code by causing an error via a javascript: URI call to document.write in the (1) FDF, (2) XML, or (3) XFDF AJAX request parameters.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/03/2025
This vulnerability represents a critical double free memory corruption flaw in Adobe Acrobat Reader Plugin versions prior to 8.0.0 that was actively exploited in web browser environments. The vulnerability specifically affects the integration between Adobe Reader and Mozilla Firefox 1.5.0.7, where the plugin fails to properly handle memory allocation and deallocation during processing of certain javascript: URI calls. The flaw manifests when malicious web content triggers document.write operations within FDF XML or XFDF AJAX request parameters, creating conditions where the same memory block gets freed twice. This double free condition occurs in the plugin's memory management routines when processing structured data formats used for form data exchange and web-based document interaction. The vulnerability is classified under CWE-415 as an improper free condition, where the application attempts to free the same memory block multiple times, leading to undefined behavior and potential code execution.
The operational impact of this vulnerability extends beyond simple memory corruption, as it provides remote attackers with a pathway to arbitrary code execution within the context of the victim's browser session. When exploited, the double free condition can be leveraged to manipulate heap memory layout, potentially allowing attackers to inject and execute malicious code with the privileges of the compromised user. This represents a significant elevation of privilege vector since Adobe Reader Plugin typically runs with elevated permissions when processing PDF documents. The attack requires a user to visit a malicious web page that triggers the vulnerable javascript: URI call sequence, making it a client-side exploitation vector that relies on social engineering or compromised websites to deliver the payload.
The exploitation mechanism involves crafting specifically formatted FDF XML or XFDF data structures that when processed through the document.write function in a javascript: URI context, trigger the memory management error. This attack pattern aligns with ATT&CK technique T1059.007 for JavaScript and T1203 for Exploitation for Client Execution, where attackers leverage browser plugin vulnerabilities to execute malicious code. The vulnerability demonstrates how web-based document processing plugins can become attack vectors when proper memory management is not implemented, particularly in environments where multiple data formats are processed through a single plugin interface. Security researchers have noted that this type of vulnerability is particularly dangerous because it can be triggered without requiring user interaction beyond visiting a malicious website, making it a preferred target for drive-by download attacks.
Mitigation strategies for this vulnerability require immediate patching of Adobe Acrobat Reader Plugin to version 8.0.0 or later, where the double free condition has been resolved through proper memory management implementation. Organizations should also implement browser security measures including disabling plugin execution for untrusted websites, using sandboxing techniques, and maintaining up-to-date security policies that restrict javascript: URI handling. Network-level protections can include web application firewalls that monitor for suspicious javascript: URI patterns and content filtering that blocks known malicious FDF XML or XFDF data structures. Additionally, users should be educated about the risks of visiting untrusted websites and the importance of keeping their browser plugins updated. The vulnerability highlights the necessity of proper input validation and memory management practices in plugin architectures, as well as the importance of following secure coding guidelines that prevent common memory corruption vulnerabilities. This case study underscores the critical relationship between web browser security and third-party plugin security, where vulnerabilities in one component can compromise the entire browser ecosystem.