CVE-2012-0584 in Safari
Summary
by MITRE
The Internationalized Domain Name (IDN) feature in Apple Safari before 5.1.4 on Windows does not properly restrict the characters in URLs, which allows remote attackers to spoof a domain name via unspecified homoglyphs.
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Analysis
by VulDB Data Team • 01/04/2025
The vulnerability identified as CVE-2012-0584 represents a critical security flaw in Apple Safari's handling of Internationalized Domain Names on Windows platforms prior to version 5.1.4. This issue stems from insufficient validation of character sequences in URL parsing, creating a pathway for malicious actors to exploit visual similarities between different character sets. The vulnerability specifically affects the browser's ability to properly distinguish between legitimate domain names and forged ones through the manipulation of homoglyph characters that appear visually identical or nearly identical to standard ASCII characters.
The technical root cause of this vulnerability lies in the improper implementation of IDN handling within Safari's URL parser, which fails to adequately sanitize or validate character sequences that could represent internationalized domain names. This flaw allows attackers to construct domain names that contain Unicode characters which visually resemble standard ASCII characters from the victim's perspective. The vulnerability operates under CWE-174, which addresses the weakness of insufficient character set validation in URL parsing mechanisms. The implementation does not properly enforce character restrictions or validate the integrity of domain name sequences, creating a mismatch between how the browser interprets and displays domain names versus how they are actually resolved.
From an operational standpoint, this vulnerability enables sophisticated phishing attacks where attackers can create domain names that appear legitimate to users while actually directing them to malicious endpoints. The attack vector leverages the visual similarity of homoglyphs from different character sets, making it particularly dangerous because users cannot easily distinguish between authentic and forged domain names through visual inspection alone. This creates a significant risk for users who rely on visual cues for domain name verification, as the browser's display mechanism fails to properly alert users to potential deception. The impact extends beyond simple phishing to potentially enable more complex attack scenarios including credential theft, malware distribution, and data exfiltration through trusted-looking but malicious web addresses.
The vulnerability demonstrates clear alignment with ATT&CK technique T1566, specifically targeting the initial access phase through deceptive web content. Security professionals should note that this issue affects not just individual users but represents a systemic flaw in browser security architecture that could be exploited at scale. The attack requires minimal technical sophistication from adversaries, making it particularly dangerous in enterprise environments where users may not be adequately trained to identify such subtle visual deceptions. Organizations should implement comprehensive security awareness training alongside technical mitigations to address this vulnerability's potential impact on user security.
Mitigation strategies should focus on immediate browser updates to version 5.1.4 or later, which contain the necessary patches to properly validate IDN character sequences. Additional protective measures include implementing URL filtering solutions that can detect and block suspicious character patterns in domain names, enabling security extensions that provide enhanced URL validation, and establishing user education programs focused on recognizing potential homoglyph-based deception. Network-level controls such as DNS sinkholing and web application firewalls can provide additional layers of defense against exploitation attempts. The vulnerability highlights the importance of proper internationalization support in security-critical applications and underscores the need for thorough testing of character handling mechanisms in web browsers and other client-side applications.