CVE-2007-0342 in OmniWeb
Summary
by MITRE
WebCore in Apple WebKit build 18794 allows remote attackers to cause a denial of service (null dereference and application crash) via a TD element with a large number in the ROWSPAN attribute, as demonstrated by a crash of OmniWeb 5.5.3 on Mac OS X 10.4.8, a different vulnerability than CVE-2006-2019.
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Analysis
by VulDB Data Team • 04/03/2025
The vulnerability described in CVE-2007-0342 represents a critical denial of service flaw within Apple WebKit's WebCore component, specifically affecting OmniWeb 5.5.3 running on Mac OS X 10.4.8. This issue stems from improper handling of HTML table elements, particularly when processing the ROWSPAN attribute within td elements. The vulnerability manifests when a maliciously crafted HTML document contains a td element with an excessively large numerical value in its ROWSPAN attribute, triggering a null dereference condition that leads to application instability and eventual crash.
The technical root cause of this vulnerability lies in the insufficient input validation and boundary checking within WebKit's HTML parser and rendering engine. When the WebCore component encounters a td element with an unusually large ROWSPAN value, it attempts to allocate memory or perform calculations based on this malformed input without proper sanitization. This flaw creates a null pointer dereference condition that crashes the entire application, effectively rendering the browser incapable of processing further content. The vulnerability is classified as a CWE-476 Null Pointer Dereference, which represents a common class of software defects where a program attempts to access memory through a null pointer reference, leading to application termination.
The operational impact of this vulnerability extends beyond simple application instability, as it represents a potential vector for remote attackers to disrupt user productivity and system availability. In a real-world scenario, an attacker could craft malicious web pages containing the problematic td element structure and deliver them through various attack vectors such as email attachments, compromised websites, or malicious advertisements. When victims access these pages using vulnerable versions of OmniWeb, the browser would immediately crash, forcing users to restart their applications and potentially lose unsaved work. This type of vulnerability also aligns with ATT&CK technique T1499.004, which involves network denial of service attacks targeting application availability.
The vulnerability demonstrates the importance of robust input validation in web browser components, particularly in HTML parsing and rendering engines that must handle arbitrary user content. WebKit's failure to properly validate the ROWSPAN attribute values creates a path for attackers to exploit memory management flaws in the browser's rendering pipeline. This issue differs from CVE-2006-2019, indicating that while both vulnerabilities involve HTML parsing, they target different code paths within the WebCore component. The specific conditions required to trigger this vulnerability - a large number in the ROWSPAN attribute - suggest that the flaw exists in how the browser handles numerical overflow or excessive allocation requests during table layout calculations.
Mitigation strategies for this vulnerability should include immediate patching of affected OmniWeb versions to incorporate proper input validation and boundary checking for HTML table attributes. System administrators should ensure that all WebKit-based browsers are updated to versions that contain the necessary security fixes. Additionally, implementing content filtering solutions that can detect and block malformed HTML content can provide an additional layer of defense. The vulnerability underscores the necessity of thorough testing of HTML parsing components against edge cases and malformed inputs, as well as the importance of following secure coding practices that prevent null pointer dereferences through proper input validation and error handling mechanisms.