CVE-2009-3832 in Web Browser
Summary
by MITRE
Opera before 10.01 on Windows does not prevent use of Web fonts in rendering the product s own user interface, which allows remote attackers to spoof the address field via a crafted web site.
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Analysis
by VulDB Data Team • 02/22/2025
The vulnerability described in CVE-2009-3832 represents a significant security flaw in Opera web browser versions prior to 10.01 on Windows operating systems. This issue stems from the browser's failure to properly isolate its user interface elements from web content rendering processes, creating a potential avenue for sophisticated phishing attacks and user interface spoofing. The vulnerability specifically affects the browser's handling of web fonts during the rendering of its own user interface components, which should normally be protected from external web content influence.
The technical implementation of this vulnerability allows remote attackers to leverage web font loading capabilities to manipulate how Opera's user interface appears to end users. When a malicious website loads specific web fonts, these fonts can be used to alter the visual presentation of the browser's address bar or other critical interface elements. This occurs because the browser's rendering engine does not adequately distinguish between system fonts used for the interface and web fonts loaded from external sources, creating a scenario where crafted web content can effectively mask or modify the browser's own UI presentation.
From an operational impact perspective, this vulnerability enables attackers to create convincing phishing attacks that can deceive users into believing they are interacting with legitimate browser functionality. The ability to spoof the address field means that users might be tricked into entering sensitive information on fraudulent websites that appear to be legitimate browser interfaces. This attack vector specifically targets user trust in the browser's interface integrity, which is fundamental to secure browsing practices and user confidence in the browser's security mechanisms.
The vulnerability aligns with CWE-200, which addresses information exposure, and represents a form of user interface deception that falls under the broader category of social engineering attacks. It also connects to ATT&CK technique T1566, which covers phishing attacks, as the vulnerability enables more sophisticated and convincing phishing attempts. The flaw demonstrates a classic lack of proper input validation and interface isolation, where the browser fails to maintain clear boundaries between its trusted interface components and potentially malicious web content. This issue highlights the importance of maintaining strict separation between browser interface rendering and web content rendering processes, particularly in preventing cross-site scripting and user interface spoofing attacks.
Mitigation strategies for this vulnerability involve updating to Opera version 10.01 or later, which implements proper font isolation mechanisms to prevent web fonts from affecting the browser's user interface rendering. Organizations should also implement comprehensive browser security policies that include regular updates and monitoring for such vulnerabilities. The fix typically involves implementing stricter font loading policies that prevent external web fonts from being used in the rendering of browser interface elements, ensuring that only system fonts or specifically trusted fonts are used for interface components. Additionally, user education regarding the importance of verifying address bar information and recognizing potential phishing attempts remains crucial in defending against exploitation of this type of vulnerability.