CVE-2002-0783 in Web Browser
Summary
by MITRE
Opera 6.01, 6.0, and 5.12 allows remote attackers to execute arbitrary JavaScript in the security context of other sites by setting the location of a frame or iframe to a Javascript: URL.
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Analysis
by VulDB Data Team • 07/03/2025
This vulnerability exists in Opera web browsers version 6.01, 6.0, and 5.12 where the browser fails to properly sanitize or validate javascript: URLs used in frame or iframe location attributes. The flaw stems from inadequate input validation mechanisms that allow malicious actors to inject javascript code through the location property of HTML frames or iframes. When a web page attempts to set the location of a frame or iframe to a javascript: URL, the browser should enforce strict security boundaries to prevent execution of arbitrary code in the context of the parent site. However, Opera versions affected by this vulnerability bypass these security checks, creating a cross-site scripting attack vector. The vulnerability is classified under CWE-79 as a Cross-Site Scripting weakness, specifically involving improper neutralization of script-related HTML tags in a web page. The attack occurs when an attacker crafts a malicious webpage that includes a frame or iframe element with a javascript: URL in its location attribute. When a user visits this page, the browser executes the javascript code within the security context of the victim site, potentially allowing the attacker to steal session cookies, perform unauthorized actions, or redirect users to malicious sites. This represents a serious security flaw that violates the fundamental principle of web browser security models, particularly the same-origin policy that prevents scripts from one origin from accessing resources from another origin. The vulnerability enables attackers to exploit trust relationships between sites, as the malicious javascript executes with the privileges and security context of the target website. From an operational perspective, this vulnerability could lead to session hijacking, data theft, and privilege escalation attacks. The attack requires no special privileges from the attacker and can be executed through simple HTML code injection, making it particularly dangerous for websites that do not properly validate or sanitize user input. The flaw essentially allows for a form of DOM-based cross-site scripting where the attack vector is embedded directly in the frame or iframe location property rather than through traditional input parameters. Security practitioners should note that this vulnerability demonstrates the critical importance of proper URL validation and the need for robust input sanitization mechanisms in web browser implementations. The mitigation strategy involves updating to newer versions of Opera where this security flaw has been addressed through improved URL parsing and validation routines. Additionally, administrators should implement proper content security policies and consider using iframe sandboxing to limit the execution scope of potentially malicious content. This vulnerability aligns with ATT&CK technique T1059.007 for JavaScript execution and represents a classic example of how browser security boundaries can be bypassed through inadequate input validation. The flaw underscores the need for comprehensive security testing of web browser implementations, particularly around URL handling and frame navigation mechanisms that form critical components of web application security architectures.