CVE-2005-0237 in Konqueror
Summary
by MITRE
The International Domain Name (IDN) support in Konqueror 3.2.1 on KDE 3.2.1 allows remote attackers to spoof domain names using punycode encoded domain names that are decoded in URLs and SSL certificates in a way that uses homograph characters from other character sets, which facilitates phishing attacks.
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Analysis
by VulDB Data Team • 06/20/2024
The vulnerability identified as CVE-2005-0237 represents a critical security flaw in Konqueror 3.2.1 web browser within the KDE 3.2.1 environment that exploits the International Domain Name (IDN) support implementation. This weakness specifically targets the browser's handling of punycode encoded domain names, creating a deceptive environment where attackers can craft malicious URLs that appear legitimate to users. The flaw leverages the ability of certain Unicode characters to visually resemble common ASCII characters, enabling attackers to create domain names that look identical or nearly identical to trusted websites while actually directing users to malicious endpoints.
The technical implementation of this vulnerability stems from how Konqueror processes IDN domain names during URL parsing and SSL certificate validation. When a user encounters a punycode encoded domain name, the browser decodes it for display purposes but fails to properly validate or warn users about potential homograph attacks. This occurs because the browser's rendering engine converts Unicode characters to their ASCII equivalents for display while maintaining the original encoded form for network communication. The flaw lies in the inconsistent handling between the visual representation and the actual network resolution, creating a mismatch that attackers can exploit to craft deceptive web addresses.
The operational impact of this vulnerability extends beyond simple phishing attempts to encompass a broader range of social engineering attacks that can compromise user trust and security. Attackers can create domain names that visually appear identical to legitimate banking, e-commerce, or government websites, potentially leading users to unknowingly submit sensitive information such as login credentials, credit card numbers, or personal data. The vulnerability is particularly dangerous because it operates at the user interface level, making it difficult for users to distinguish between legitimate and malicious sites based on visual appearance alone. This type of attack directly violates the principle of least privilege and undermines user confidence in digital security measures.
The vulnerability aligns with CWE-1004, which addresses insecure default settings in security-critical applications, and represents a classic example of a homograph attack pattern that has been documented in various security frameworks including the ATT&CK matrix under the T1566 technique for social engineering. Organizations using affected versions of Konqueror should implement immediate mitigations including disabling IDN support, implementing proper user education about URL verification, and deploying network-level controls to detect and block suspicious domain name patterns. Additionally, this vulnerability highlights the importance of proper input validation and consistent character set handling in web browser implementations, as recommended by security standards such as the OWASP Top Ten and NIST guidelines for secure web application development.
The remediation approach should include updating to patched versions of Konqueror and KDE that properly handle IDN domain names with appropriate warnings and validation mechanisms. System administrators should also consider implementing browser security policies that enforce stricter domain name validation, deploy DNS-based security controls, and establish monitoring systems to detect potential homograph attack patterns. The vulnerability serves as a critical reminder of the challenges associated with internationalization in security-critical applications and the need for comprehensive testing of character encoding behaviors in web browsers to prevent similar issues in future implementations.