CVE-2012-6462 in Web Browser
Summary
by MITRE
Opera before 12.10 does not properly implement the Cross-Origin Resource Sharing (CORS) specification, which allows remote attackers to bypass intended page-content restrictions via a crafted request.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/19/2021
The vulnerability identified as CVE-2012-6462 represents a critical implementation flaw in Opera browsers prior to version 12.10, specifically concerning the Cross-Origin Resource Sharing protocol. This weakness stems from the browser's incomplete adherence to the CORS specification, which is designed to provide secure cross-domain resource access controls. The flaw enables malicious actors to circumvent security restrictions that should prevent unauthorized access to content across different origins, fundamentally undermining the web's security model. The issue is particularly concerning because it affects one of the most widely used browsers at the time, potentially exposing millions of users to cross-site scripting and data exfiltration attacks.
The technical implementation error manifests in Opera's failure to properly validate and enforce CORS headers when processing cross-origin requests. This allows attackers to craft malicious requests that appear to originate from legitimate domains while actually accessing resources that should be restricted. The vulnerability exploits the gap between the browser's interpretation of CORS policies and the actual security requirements defined in the specification. Attackers can leverage this flaw to bypass same-origin policy restrictions that are fundamental to web security, potentially accessing sensitive data, cookies, or resources that should be protected from cross-origin access.
From an operational perspective, this vulnerability creates significant risks for web applications and users alike. Web applications that rely on CORS for security boundaries become vulnerable to attacks that can steal session cookies, access protected APIs, or retrieve sensitive information from authenticated sessions. The impact extends beyond individual user sessions to potentially compromise entire web applications that depend on CORS for their security model. This vulnerability particularly affects web applications that implement CORS-based access controls for APIs, user authentication systems, and content management platforms where proper origin validation is critical for maintaining security boundaries.
Organizations and users should immediately update to Opera version 12.10 or later, which contains the necessary fixes for proper CORS implementation. Security administrators should also review their web application configurations to ensure that CORS policies are properly enforced at both the browser and server levels. The vulnerability aligns with CWE-693, which covers protection mechanism failures, and maps to ATT&CK technique T1071.001 for application layer protocol, as it exploits weaknesses in web browser protocol implementation. Additional mitigations include implementing Content Security Policy headers, using proper origin validation on servers, and monitoring for suspicious cross-origin requests that may indicate exploitation attempts.