CVE-2008-4514 in Konqueror
Summary
by MITRE
The HTML parser in KDE Konqueror 3.5.9 allows remote attackers to cause a denial of service (application crash) via a font tag with a long color value, which triggers an assertion error.
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Analysis
by VulDB Data Team • 05/25/2025
The vulnerability identified as CVE-2008-4514 represents a classic buffer overflow condition within the HTML parsing component of KDE Konqueror version 3.5.9. This issue manifests when the application encounters a font tag containing an excessively long color value attribute, triggering an assertion error that ultimately leads to application crash and denial of service. The flaw exists in the parser's handling of malformed HTML input, specifically targeting the color attribute processing within font tags. The vulnerability demonstrates a fundamental lack of input validation and bounds checking in the HTML rendering engine, creating a predictable crash scenario that remote attackers can exploit through crafted web content.
The technical implementation of this vulnerability stems from insufficient boundary checking within the HTML parser's string handling routines. When Konqueror processes a font tag with an abnormally long color value, the parser fails to properly validate the input length before attempting to process the attribute. This condition falls under CWE-129, which addresses insufficient validation of length of input buffers, and CWE-676, which covers use of potentially dangerous functions. The assertion error occurs because the parser's internal buffer management cannot accommodate the excessive string length, leading to memory corruption that terminates the application process. This type of vulnerability represents a common pattern in legacy web browsers where input sanitization was not adequately implemented.
The operational impact of CVE-2008-4514 extends beyond simple application instability to represent a significant security concern for users of KDE Konqueror. Remote attackers can leverage this vulnerability to disrupt user sessions and potentially gain unauthorized access to system resources through persistent denial of service attacks. The vulnerability operates at the application layer of the OSI model, specifically affecting the presentation layer where HTML content is rendered. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and T1566.001, representing spearphishing through social engineering. The attack vector is particularly concerning as it requires no privileged access or user interaction beyond visiting a malicious website, making it an attractive target for automated exploitation.
Mitigation strategies for CVE-2008-4514 should focus on immediate patching of the affected KDE Konqueror version, as this represents a critical security flaw that has been addressed in subsequent releases. System administrators should implement network-level protections through web application firewalls that can detect and block malformed HTML content containing excessively long attribute values. Additionally, browser isolation techniques and sandboxing can provide defense-in-depth measures to limit the impact of successful exploitation attempts. The vulnerability highlights the importance of input validation and proper error handling in web browser implementations, serving as a reminder that even seemingly benign HTML elements can represent security risks when not properly constrained. Organizations should also consider implementing security awareness training to educate users about the risks of visiting untrusted websites and the potential for drive-by download attacks that may exploit such vulnerabilities.