CVE-2005-2522 in Mac OS X
Summary
by MITRE
Safari in WebKit in Mac OS X 10.4 to 10.4.2 directly accesses URLs within PDF files without the normal security checks, which allows remote attackers to execute arbitrary code via links in a PDF file.
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Analysis
by VulDB Data Team • 07/19/2024
This vulnerability exists in Apple Safari browser's WebKit rendering engine implementation within Mac OS X versions 10.4 through 10.4.2. The flaw represents a critical security bypass that occurs when the browser processes embedded hyperlinks within PDF documents. When users open PDF files containing malicious URLs, Safari directly navigates to these addresses without performing the standard security validations that typically occur during normal web browsing operations. This behavior creates an exploitable condition where remote attackers can craft malicious PDF documents containing specially crafted links that, when opened in Safari, automatically execute arbitrary code on the victim's system. The vulnerability stems from insufficient input validation and security boundary enforcement within the PDF handling component of the WebKit framework, allowing unauthorized code execution through the PDF rendering pipeline.
The technical implementation of this vulnerability involves a failure in the URL handling mechanism within Safari's PDF processing subsystem. When a PDF file contains embedded hyperlinks, the browser should normally validate these references against security policies and potentially warn users before executing navigation. However, this vulnerability allows direct execution of URLs without such checks, effectively bypassing the browser's security model. The flaw operates at the intersection of web browsing and document rendering, where PDF links are treated differently from regular web URLs, creating a security gap that malicious actors can exploit. This represents a classic case of insufficient privilege separation between different content types within the browser's security architecture, where the PDF viewer component does not properly enforce the same security restrictions applied to web content.
The operational impact of this vulnerability is severe and far-reaching, as it enables remote code execution attacks that can compromise entire user systems. Attackers can distribute malicious PDF files through various vectors including email attachments, compromised websites, or social engineering campaigns, making exploitation relatively straightforward. Once a user opens the malicious PDF in Safari, the attacker's code executes with the privileges of the browser process, potentially allowing for full system compromise, data theft, or further attack escalation. The vulnerability affects a significant user base as Mac OS X 10.4 and its subsequent versions were widely deployed, making this an attractive target for cybercriminals. Additionally, the automatic execution of links without user confirmation creates a zero-day exploitation opportunity where users are unaware of the malicious activity until it's too late, as the system performs the navigation without any security warnings or user interaction requirements.
This vulnerability aligns with CWE-20, which describes improper input validation, and demonstrates characteristics consistent with ATT&CK technique T1203, involving exploitation of web applications through malicious links. The security implications extend beyond simple code execution to include potential privilege escalation and persistent threats. Organizations should implement immediate mitigations including updating to patched versions of Mac OS X, disabling PDF viewing in Safari, or implementing network-level filtering to block suspicious PDF content. The vulnerability also highlights the importance of proper security boundaries between different content types within browser architectures, as the PDF rendering component should not have direct access to network resources without appropriate security validation. System administrators should consider implementing additional security measures such as sandboxing PDF processing components and monitoring for unusual network activity that might indicate exploitation attempts. The incident underscores the critical need for comprehensive security testing of integrated components within complex software ecosystems where different functionalities interact with each other.