CVE-2004-0872 in Web Browser
Summary
by MITRE
Opera does not prevent cookies that are sent over an insecure channel (HTTP) from also being sent over a secure channel (HTTPS/SSL) in the same domain, which could allow remote attackers to steal cookies and conduct unauthorized activities, aka "Cross Security Boundary Cookie Injection."
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 04/22/2019
This vulnerability in Opera browsers represents a critical security flaw that violates fundamental principles of web security architecture and cookie management. The issue stems from Opera's improper handling of cookie transmission across different security contexts within the same domain, creating a dangerous cross-security boundary injection scenario. When cookies are transmitted over an insecure HTTP channel, the browser fails to enforce proper security boundaries that would normally prevent these cookies from being automatically included in subsequent secure HTTPS requests. This behavior directly contravenes established web security practices and creates a pathway for attackers to exploit session management mechanisms across different security levels.
The technical implementation flaw lies in Opera's cookie handling logic which does not properly validate or restrict cookie transmission based on the security context of the connection. When a user accesses a website via HTTP and receives cookies, these cookies should not automatically be transmitted when the same domain is subsequently accessed via HTTPS. However, Opera's implementation allows cookies received over HTTP to be seamlessly transferred to HTTPS connections, effectively bypassing the security model that separates insecure and secure communication channels. This behavior creates a scenario where session tokens and authentication cookies can be inadvertently shared across security boundaries, potentially enabling attackers to hijack sessions or perform unauthorized actions.
The operational impact of this vulnerability is significant as it enables attackers to perform session hijacking and authentication bypass attacks without requiring additional exploitation techniques. An attacker who successfully compromises an HTTP session can potentially leverage this flaw to gain access to secure HTTPS sessions within the same domain, effectively elevating their privileges and expanding their attack surface. This vulnerability particularly affects web applications that rely on cookie-based authentication mechanisms, as the attacker can exploit the cross-security boundary behavior to steal session cookies and impersonate legitimate users. The attack vector is relatively straightforward since it only requires the attacker to establish an initial insecure connection and then perform subsequent secure connections to the same domain.
This vulnerability maps directly to CWE-1004 which describes insecure cookie handling and the improper restriction of operations within a security context. The flaw also aligns with ATT&CK technique T1566 which covers credential access through the exploitation of web application vulnerabilities. The issue demonstrates a fundamental failure in the browser's security boundary enforcement mechanisms and represents a classic example of how improper implementation of security controls can create exploitable conditions. Organizations using Opera browsers are particularly vulnerable to attacks that target session management, especially in environments where sensitive data is transmitted over HTTPS while the initial access point remains insecure.
Mitigation strategies should focus on both browser-level and application-level protections. Browser vendors should implement proper cookie security boundary enforcement that prevents insecure cookies from being transmitted over secure channels, which aligns with the security recommendations outlined in RFC 6265 for cookie handling. Application developers should implement additional security measures such as using the Secure and HttpOnly flags on cookies, implementing proper session management controls, and ensuring that sensitive operations are protected through multiple authentication factors. Organizations should also consider implementing network-level protections such as HSTS (HTTP Strict Transport Security) to force secure connections and prevent downgrade attacks that could exploit this vulnerability. Regular security assessments and penetration testing should be conducted to identify and remediate similar cross-security boundary issues in web applications and browser implementations.