CVE-2007-3142 in Web Browser
Summary
by MITRE
Visual truncation vulnerability in Opera 9.21 allows remote attackers to spoof the address bar and possibly conduct phishing attacks via a long hostname, which is truncated after 34 characters, as demonstrated by a phishing attack using HTTP Basic Authentication.
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Analysis
by VulDB Data Team • 07/20/2019
The visual truncation vulnerability in Opera 9.21 represents a significant security flaw that exploits the browser's handling of long hostnames in the address bar. This vulnerability stems from the browser's decision to truncate hostnames after 34 characters, creating a deceptive user interface that can mislead users about the true destination of web requests. The flaw specifically impacts the visual representation of URLs, where attackers can craft malicious hostnames that appear legitimate when truncated, while the full hostname reveals the true malicious intent. This issue directly relates to CWE-184, which addresses incomplete input validation and improper handling of input data that can lead to security vulnerabilities. The vulnerability enables attackers to manipulate the visual presentation of URLs in a manner that violates user expectations and trust in the browser's address bar.
The technical implementation of this vulnerability involves Opera's address bar rendering mechanism that automatically truncates hostnames exceeding 34 characters. When an attacker crafts a malicious hostname that is longer than 34 characters, the browser displays only the first 34 characters in the address bar, effectively hiding the remainder of the domain name. This truncation creates a scenario where legitimate domains can appear to be part of a trusted website when the truncated portion is not visible to users. The vulnerability becomes particularly dangerous when combined with HTTP Basic Authentication, as demonstrated in phishing attacks where the truncated address bar can make malicious sites appear to be legitimate services. The flaw operates at the application layer of the network stack and represents a user interface security issue that undermines the fundamental trust model of web browsers.
The operational impact of this vulnerability extends beyond simple visual deception to enable sophisticated phishing attacks that can bypass user security awareness. Attackers can construct hostnames that begin with legitimate domain names followed by malicious subdomains or paths that are hidden due to truncation. This allows them to create convincing fake login pages that appear to be legitimate services when viewed in the browser's address bar. The vulnerability creates a trust boundary violation where users cannot accurately verify the true destination of web requests based on visual cues alone. Security researchers have noted that this type of vulnerability falls under the ATT&CK technique T1566, which describes social engineering attacks that manipulate user perception through visual deception. The attack vector requires minimal technical expertise and can be executed against users who rely on visual verification of website addresses.
Mitigation strategies for this vulnerability must address both the immediate visual truncation issue and broader security implications for browser design. Users should be advised to verify full URLs including the complete hostname rather than relying solely on truncated address bar displays. Browser vendors should implement more robust URL display mechanisms that either prevent truncation or clearly indicate when content has been truncated. The vulnerability highlights the importance of implementing proper input validation and display handling as outlined in security standards such as the OWASP Top Ten. Organizations should consider implementing additional security measures such as URL reputation services and enhanced user education about verifying complete URLs. Security patches for this vulnerability would typically involve modifying the browser's address bar rendering logic to either prevent truncation of hostnames or provide clear visual indicators when content has been truncated, ensuring that users can make informed decisions about their web browsing activities.