CVE-2007-0537 in Konqueror
Summary
by MITRE
The KDE HTML library (kdelibs), as used by Konqueror 3.5.5, does not properly parse HTML comments, which allows remote attackers to conduct cross-site scripting (XSS) attacks and bypass some XSS protection schemes by embedding certain HTML tags within a comment in a title tag, a related issue to CVE-2007-0478.
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Analysis
by VulDB Data Team • 07/15/2019
The vulnerability identified as CVE-2007-0537 resides within the KDE HTML library known as kdelibs which serves as the foundational web rendering component for the Konqueror web browser version 3.5.5. This flaw represents a critical security weakness that directly impacts how the browser processes HTML content, specifically concerning the parsing of HTML comments. The vulnerability stems from insufficient input validation and sanitization mechanisms within the HTML parsing engine, creating a pathway for malicious actors to exploit the browser's rendering capabilities.
The technical flaw manifests when the HTML parser encounters malformed or improperly structured HTML comments that contain embedded HTML tags within the title tag. The kdelibs library fails to properly sanitize or neutralize these embedded tags during the parsing process, allowing them to be executed as part of the web page rendering cycle. This improper handling occurs specifically within the comment parsing logic where the system does not adequately distinguish between legitimate comment content and potentially malicious embedded HTML elements. The vulnerability is particularly concerning because it allows attackers to bypass existing XSS protection mechanisms that rely on proper HTML comment parsing and validation.
From an operational standpoint, this vulnerability creates significant risks for users browsing the web with Konqueror 3.5.5, as it enables remote attackers to execute arbitrary JavaScript code within the browser context. The attack vector involves crafting malicious web pages that contain specially formatted HTML comments with embedded tags in the title element, which can then be executed when the page loads in the vulnerable browser. This allows attackers to perform various malicious activities including cookie theft, session hijacking, redirection to malicious sites, and execution of arbitrary code on the victim's system. The vulnerability particularly impacts users who may encounter compromised websites or those who are tricked into visiting malicious pages that exploit this specific parsing flaw.
The security implications of CVE-2007-0537 align with CWE-79 which describes Cross-Site Scripting vulnerabilities, and the attack pattern corresponds to ATT&CK technique T1059.007 for JavaScript execution. The vulnerability demonstrates a classic case of insufficient input sanitization where the HTML parser fails to properly validate content within comment sections. This weakness creates a bypass scenario for XSS protection schemes that typically focus on direct input validation rather than indirect execution paths through comment parsing. Organizations using Konqueror 3.5.5 should immediately implement mitigations including browser updates, input filtering mechanisms, and user education about avoiding untrusted web content. Additionally, the vulnerability highlights the importance of comprehensive HTML parsing validation that covers all potential content injection vectors including comment sections, which is essential for maintaining secure web browsing environments.
This vulnerability serves as a reminder of the critical importance of proper HTML parsing validation in web browsers and demonstrates how seemingly minor parsing inconsistencies can create significant security risks. The flaw represents a fundamental weakness in the HTML processing pipeline that can be exploited to circumvent security controls, emphasizing the need for robust input validation across all components of web browser architectures. The vulnerability's relationship to CVE-2007-0478 further underscores the systematic nature of HTML parsing flaws that can affect multiple aspects of web content processing and security enforcement mechanisms within browser applications.