CVE-2009-2063 in Web Browser
Summary
by MITRE
Opera, possibly before 9.25, processes a 3xx HTTP CONNECT response before a successful SSL handshake, which allows man-in-the-middle attackers to execute arbitrary web script, in an https site s context, by modifying this CONNECT response to specify a 302 redirect to an arbitrary https web site.
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Analysis
by VulDB Data Team • 09/06/2019
The vulnerability described in CVE-2009-2063 represents a critical flaw in Opera web browser's handling of HTTP CONNECT requests during SSL/TLS handshakes. This issue affects Opera versions prior to 9.25 and stems from the browser's improper processing sequence of HTTP responses in secure connections. The vulnerability specifically occurs when Opera receives a 3xx HTTP redirect response to a CONNECT request before completing the SSL handshake process, creating a window of opportunity for malicious actors to exploit the connection handling mechanism.
The technical flaw exploits the order of operations in Opera's secure connection establishment process. During HTTPS browsing, browsers typically establish a TCP connection to a proxy server using the CONNECT method, then proceed with the SSL handshake to secure the communication channel. In this vulnerability, Opera processes the 3xx redirect response from the CONNECT request before the SSL handshake completes, allowing attackers to manipulate the redirect behavior. The flaw enables attackers to inject malicious web scripts into the context of an HTTPS site, effectively bypassing the security mechanisms that should protect against such attacks.
This vulnerability has significant operational impact as it allows man-in-the-middle attackers to execute arbitrary web scripts within the security context of HTTPS sites. The attack vector specifically targets the HTTP CONNECT method handling, where an attacker can modify a CONNECT response to include a 302 redirect to an arbitrary HTTPS website. This manipulation enables the execution of malicious code in the context of the original HTTPS site, potentially leading to session hijacking, data theft, or further exploitation of the victim's browser. The vulnerability essentially undermines the fundamental security promise of HTTPS encryption by allowing attackers to inject content before the secure connection is properly established.
The security implications of this vulnerability align with CWE-345 Insufficient Verification of Data Authenticity, as Opera fails to properly verify the authenticity of the CONNECT response before proceeding with connection establishment. From an ATT&CK framework perspective, this vulnerability maps to T1571 Multi-hop Proxy and T1071.004 Application Layer Protocol: DNS, as it exploits the HTTP protocol's handling of proxy connections. The vulnerability also relates to T1212 Exploitation for Credential Access and T1566 Impersonation, as it enables attackers to impersonate legitimate HTTPS sites and gain access to user credentials or sensitive information. Organizations should immediately update to Opera 9.25 or later versions, implement network monitoring for suspicious CONNECT requests, and consider deploying proxy security solutions that can detect and block malicious redirect responses. The vulnerability underscores the importance of proper SSL/TLS handshake sequencing and the need for robust verification mechanisms in secure communication protocols, particularly in proxy handling scenarios where multiple protocol layers interact.