CVE-2010-0050 in Safari
Summary
by MITRE
Use-after-free vulnerability in WebKit in Apple Safari before 4.0.5 allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via an HTML document with improperly nested tags.
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Analysis
by VulDB Data Team • 05/02/2026
The CVE-2010-0050 vulnerability represents a critical use-after-free flaw within the WebKit rendering engine that powered Apple Safari browsers prior to version 4.0.5. This vulnerability falls under the CWE-416 category, which specifically addresses use-after-free conditions where memory is accessed after it has been freed, creating a dangerous scenario for remote code execution. The flaw manifests when Safari processes HTML documents containing improperly nested tags, which triggers memory management errors in the browser's rendering pipeline. The vulnerability is particularly concerning because it enables remote attackers to craft malicious web pages that can exploit this memory corruption issue to execute arbitrary code on affected systems or cause application crashes that result in denial of service conditions.
The technical exploitation of this vulnerability occurs through the improper handling of HTML tag nesting structures within WebKit's DOM parsing and rendering mechanisms. When Safari encounters malformed HTML with incorrectly nested tags, the browser's memory management system fails to properly track the lifecycle of allocated memory blocks, leading to situations where freed memory locations are accessed again. This memory corruption can be leveraged by attackers to overwrite critical memory locations, potentially allowing them to inject and execute malicious code with the privileges of the browser process. The vulnerability demonstrates how seemingly benign HTML parsing operations can result in severe security implications when memory management is not properly enforced.
The operational impact of CVE-2010-0050 extends beyond simple application crashes to represent a significant threat vector for attackers seeking to compromise Safari users. This vulnerability affects all versions of Apple Safari prior to 4.0.5, making it particularly dangerous given the widespread deployment of these older browser versions across enterprise and consumer environments. The remote exploitation capability means that attackers can deliver malicious payloads through standard web browsing activities without requiring any special privileges or user interaction beyond visiting a compromised website. The vulnerability's classification under the ATT&CK framework as a remote code execution technique demonstrates its potential for enabling broader attack chains, including privilege escalation and persistent access to compromised systems.
Mitigation strategies for this vulnerability require immediate patching of affected Safari installations to version 4.0.5 or later, which contains the necessary memory management fixes. Organizations should implement comprehensive browser update policies to ensure all systems receive security patches promptly. Additional defensive measures include deploying web application firewalls that can detect and block malformed HTML content, implementing browser security policies that restrict potentially dangerous HTML features, and educating users about the risks of visiting untrusted websites. The vulnerability highlights the importance of regular security assessments and the need for robust memory safety practices in browser engine development, particularly in the context of modern web standards that increasingly rely on complex rendering pipelines and dynamic content manipulation.