CVE-2003-0284 in Acrobat
Summary
by MITRE
Adobe Acrobat 5 does not properly validate JavaScript in PDF files, which allows remote attackers to write arbitrary files into the Plug-ins folder that spread to other PDF documents, as demonstrated by the W32.Yourde virus.
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Analysis
by VulDB Data Team • 07/15/2024
Adobe Acrobat 5.0 and earlier versions contain a critical security vulnerability in their JavaScript processing engine that fails to properly validate malicious script content within PDF documents. This vulnerability resides in the software's handling of embedded JavaScript code and represents a classic example of insufficient input validation that allows for arbitrary code execution and file manipulation. The flaw specifically affects the Acrobat reader's interpretation of JavaScript commands embedded within PDF files, creating an environment where attacker-controlled scripts can bypass normal security restrictions and execute with elevated privileges.
The technical implementation of this vulnerability stems from Adobe's inadequate sanitization of JavaScript code during PDF processing, particularly when handling the Plug-ins directory. When a malicious PDF document containing crafted JavaScript is opened, the vulnerable Acrobat version fails to properly validate the script's intent and destination paths, allowing the malicious code to write files directly to the Acrobat Plug-ins folder. This directory is automatically loaded by Acrobat upon startup, creating a persistent infection mechanism that spreads malware across multiple PDF documents. The vulnerability specifically exploits the lack of proper path validation and access control checks within the Acrobat JavaScript engine, enabling attackers to execute arbitrary file operations without proper authorization.
The operational impact of this vulnerability extends far beyond simple file corruption, as it enables sophisticated malware distribution mechanisms like the W32.Yourde virus that demonstrated this weakness. The malicious JavaScript code can create new files in the Plug-ins directory, which are then automatically loaded by Acrobat when processing subsequent PDF documents, creating a propagation mechanism that spreads the infection across multiple systems and documents. This represents a significant threat to enterprise environments where PDF documents are frequently exchanged, as the infection can spread silently through normal document workflows. The vulnerability allows for persistent malware deployment that can execute without user interaction, making it particularly dangerous for organizations with limited security awareness training.
Security researchers have classified this vulnerability under CWE-20, which describes improper input validation, and it aligns with several ATT&CK techniques including T1059.007 for JavaScript execution and T1566 for social engineering through malicious documents. Organizations should immediately implement mitigation strategies including updating to Adobe Acrobat 5.0.5 or later versions that contain proper JavaScript validation patches. Additional protective measures include implementing PDF content filtering solutions, restricting Acrobat's ability to write to system directories, and deploying network-based intrusion detection systems that can identify malicious JavaScript patterns. Security administrators should also consider disabling JavaScript execution entirely in Acrobat settings when it is not required for business operations, as this provides an additional layer of defense against similar vulnerabilities. The vulnerability demonstrates the importance of proper input validation in security-critical applications and highlights the need for regular security updates and patch management processes to prevent exploitation of known weaknesses in widely deployed software applications.