CVE-2007-5020 in Acrobat Reader
Summary
by MITRE
Unspecified vulnerability in Adobe Acrobat and Reader 8.1 on Windows allows remote attackers to execute arbitrary code via a crafted PDF file, related to the mailto: option and Internet Explorer 7 on Windows XP. NOTE: this information is based upon a vague pre-advisory by a reliable researcher.
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Analysis
by VulDB Data Team • 06/04/2025
This vulnerability resides within Adobe Acrobat and Reader version 8.1 on Windows systems, representing a critical remote code execution flaw that leverages the mailto: protocol functionality within PDF documents. The vulnerability specifically manifests when these applications process crafted PDF files that contain malicious mailto: links, particularly in environments where Internet Explorer 7 is installed on Windows XP operating systems. The technical mechanism involves the improper handling of URL schemes within PDF documents, where the application fails to adequately validate or sanitize user input from maliciously constructed PDF content. This allows attackers to craft PDF files that, when opened or processed by the vulnerable software, can trigger arbitrary code execution within the context of the user's privileges. The attack vector is particularly concerning because it exploits the integration between Adobe's PDF processing capabilities and Internet Explorer's handling of mailto: protocols, creating a chain of execution that bypasses normal security boundaries. The vulnerability demonstrates a classic lack of input validation and sanitization that aligns with CWE-170, which addresses issues with improper input handling and the use of potentially dangerous functions. The exploitability of this vulnerability is enhanced by the prevalence of Internet Explorer 7 on Windows XP systems during the time this vulnerability was active, as well as the widespread use of Adobe Acrobat and Reader software in enterprise and personal environments. The remote nature of the attack means that an attacker can deliver the malicious PDF file through various means including email attachments, web downloads, or malicious websites without requiring local system access. This vulnerability directly impacts the principle of least privilege and can potentially allow attackers to escalate privileges or execute malicious payloads that could compromise the entire system. The issue is particularly significant in enterprise environments where Adobe Reader is commonly deployed and where users may not be security-savvy enough to avoid opening suspicious PDF files. The attack scenario typically involves a user opening a malicious PDF file that contains embedded mailto: links designed to trigger code execution through Internet Explorer's handling of these protocols. The vulnerability affects the application's security model by failing to properly isolate the PDF processing environment from the underlying operating system and browser components. This flaw represents a failure in secure coding practices and demonstrates the importance of proper input validation and boundary checking in security-critical applications. The impact extends beyond simple code execution to potentially enable full system compromise, data exfiltration, and persistence mechanisms within compromised systems. Organizations should implement immediate mitigations including patching to the latest Adobe Reader versions, disabling PDF processing in web browsers, and implementing strict email filtering policies to prevent delivery of potentially malicious PDF attachments. The vulnerability also highlights the risks associated with legacy software environments and underscores the importance of maintaining up-to-date security patches across all software components. This type of vulnerability falls under the ATT&CK framework category of Execution through the use of malicious PDF files and browser-based exploits, potentially leading to privilege escalation and lateral movement within compromised networks. The remediation process requires not only patching the specific vulnerability but also addressing the broader security posture of systems that may be running outdated software versions that could be susceptible to similar exploitation techniques.