CVE-2010-4044 in Web Browser
Summary
by MITRE
Opera before 10.63 does not ensure that the portion of a URL shown in the Address Bar contains the beginning of the URL, which allows remote attackers to spoof URLs by changing a window s size.
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Analysis
by VulDB Data Team • 09/28/2021
The vulnerability identified as CVE-2010-4044 affects Opera web browsers versions prior to 10.63 and represents a significant user interface spoofing flaw that undermines the browser's security model. This issue stems from the browser's failure to properly validate and display URL components within the address bar, creating a scenario where malicious actors can exploit the visual presentation of web addresses to deceive users into believing they are visiting legitimate websites when they are actually navigating to malicious domains.
The technical flaw manifests when the browser's address bar displays URLs that have been manipulated through window resizing operations. In affected versions of Opera, the address bar may truncate or modify the visible portion of a URL, particularly showing only the end portion of the address while concealing the beginning where the malicious domain is typically located. This occurs because the browser's rendering engine does not enforce consistent display policies for URL components, allowing attackers to manipulate the visual representation by altering window dimensions to force the display of truncated URL segments.
This vulnerability operates under the broader category of user interface deception attacks and aligns with CWE-693, which covers protection mechanism failures in software systems. The flaw specifically enables attackers to craft URLs where the visible portion contains legitimate domain components while the hidden beginning contains malicious elements, making it appear as though users are visiting trusted websites. The attack vector is particularly insidious because it leverages the browser's legitimate window resizing functionality to create visual deception rather than requiring complex code injection or other advanced exploitation techniques.
The operational impact of this vulnerability extends beyond simple phishing attacks to encompass various forms of social engineering and credential theft. Attackers can exploit this flaw to create convincing fake login pages that appear legitimate to users who are simply browsing with standard window sizes, as the address bar may display only the final portion of a URL that contains the trusted domain name. This creates a false sense of security for users who may not notice the discrepancy between the displayed address and the actual destination, potentially leading to the compromise of sensitive information such as login credentials, financial data, or personal identifiers.
The vulnerability demonstrates the critical importance of user interface security design and the need for comprehensive validation of visual elements that users rely upon for security decisions. Security professionals should recognize this issue as part of the broader ATT&CK framework's T1566 category related to credential access through social engineering techniques. The flaw highlights the necessity of implementing robust URL display policies that ensure users always see the complete and accurate representation of web addresses, regardless of window dimensions or browser configurations.
Mitigation strategies for CVE-2010-4044 require immediate updates to Opera browser versions to 10.63 or later, where the issue has been resolved through improved URL display validation mechanisms. Organizations should also implement user education programs to raise awareness about the importance of verifying complete URLs rather than relying solely on address bar visual cues. Additionally, network monitoring solutions should be configured to detect suspicious URL patterns and unusual window resizing behaviors that may indicate attempts to exploit this vulnerability. The fix implemented in newer Opera versions typically involves enforcing consistent URL truncation policies and ensuring that the address bar always displays the complete domain information regardless of browser window dimensions.