CVE-2010-3813 in Safari
Summary
by MITRE
The WebCore::HTMLLinkElement::process function in WebCore/html/HTMLLinkElement.cpp in WebKit, as used in Apple Safari before 5.0.3 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1.3 on Mac OS X 10.4; webkitgtk before 1.2.6; and possibly other products does not verify whether DNS prefetching is enabled when processing an HTML LINK element, which allows remote attackers to bypass intended access restrictions, as demonstrated by an HTML e-mail message that uses a LINK element for X-Confirm-Reading-To functionality.
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Analysis
by VulDB Data Team • 10/05/2021
The vulnerability described in CVE-2010-3813 represents a critical security flaw in WebKit's HTML link processing mechanism that affects multiple browser implementations including Apple Safari and webkitgtk. This issue stems from the WebCore::HTMLLinkElement::process function which fails to validate DNS prefetching status when handling HTML LINK elements. The flaw exists in the core HTML processing logic where the system does not properly check whether DNS prefetching has been enabled before executing link processing operations, creating a potential bypass mechanism for access restrictions.
The technical implementation of this vulnerability occurs within the WebCore/html/HTMLLinkElement.cpp file where the process function handles HTML LINK elements without proper validation of DNS prefetching settings. When an attacker crafts an HTML email message containing a LINK element with X-Confirm-Reading-To functionality, the vulnerable system processes this element without verifying if DNS prefetching is enabled, thereby allowing unauthorized access to resources that should be restricted. This behavior creates a pathway for remote attackers to circumvent intended security controls through carefully constructed HTML content.
The operational impact of this vulnerability extends across multiple platforms and versions, affecting Apple Safari versions before 5.0.3 on Mac OS X 10.5 through 10.6 and Windows, as well as webkitgtk versions before 1.2.6 and Mac OS X 10.4 before 4.1.3. The exploitation demonstrates how attackers can leverage this flaw in email-based attacks where HTML content is processed by vulnerable browsers, potentially enabling unauthorized network access or information disclosure. This vulnerability particularly impacts email clients and web browsers that process HTML content from untrusted sources, creating a significant risk for users who receive HTML emails from potentially malicious sources.
This vulnerability maps to CWE-693, which covers Protection Mechanism Failure, specifically related to the improper implementation of access control mechanisms. The flaw represents a failure in the validation process that should ensure DNS prefetching is properly enabled before executing link processing operations. From an attack perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under T1190 for Exploit Public-Facing Application, where attackers exploit web application vulnerabilities to gain unauthorized access. The vulnerability essentially allows attackers to bypass network-level access controls through manipulation of HTML content processing.
The primary mitigation strategies involve updating affected browser implementations to versions that properly validate DNS prefetching settings before processing HTML LINK elements. System administrators should ensure that all affected Safari installations are updated to version 5.0.3 or later, and webkitgtk installations to version 1.2.6 or later. Additionally, organizations should implement email filtering measures that sanitize HTML content and disable potentially dangerous LINK element processing. Network-level protections should include monitoring for unusual DNS prefetching activity and implementing proper access controls to prevent unauthorized resource access. The vulnerability highlights the importance of proper input validation and access control implementation in web browser components, particularly in HTML processing functions that handle user-provided content.