CVE-2002-2414 in Web Browser
Summary
by MITRE
Opera 6.0.3, when using Squid 2.4 for HTTPS proxying, does not properly handle when accepting a non-global certificate authority (CA) certificate from a site and establishing a subsequent HTTPS connection, which allows remote attackers to cause a denial of service (crash).
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Analysis
by VulDB Data Team • 10/28/2024
This vulnerability exists in Opera 6.0.3 version when configured to use Squid 2.4 as an HTTPS proxy server. The flaw occurs during the certificate validation process where Opera fails to properly handle certificate authority certificates that are not globally recognized or trusted. When a website presents a certificate signed by a non-global CA, Opera's certificate handling mechanism becomes unstable and crashes when establishing subsequent HTTPS connections. This represents a classic certificate validation error that can be exploited to cause denial of service conditions.
The technical implementation of this vulnerability stems from Opera's inadequate certificate chain validation when operating through the Squid proxy environment. The browser's SSL/TLS stack does not properly sanitize or validate certificate authorities that are not part of the standard trusted root certificate store. When a malicious website presents a certificate from a non-global CA, Opera's certificate processing logic encounters an unexpected state that leads to a crash rather than gracefully handling the validation failure or prompting user intervention. This behavior aligns with CWE-248, which addresses improper exception handling in software systems.
The operational impact of this vulnerability extends beyond simple denial of service as it creates a potential attack vector that could be exploited in various scenarios. An attacker could craft malicious web content that presents certificates from untrusted or non-global CAs, causing Opera users who are configured to use Squid 2.4 as a proxy to experience browser crashes. This vulnerability particularly affects users in enterprise environments where Squid proxies are commonly deployed, as the proxy configuration creates a specific attack surface. The vulnerability does not appear to allow for arbitrary code execution or data theft, but rather focuses on disrupting service availability through browser crashes.
From a security framework perspective, this vulnerability demonstrates poor certificate validation practices that could be categorized under ATT&CK technique T1566 for initial access through phishing or malicious content delivery. The attack requires minimal prerequisites as it only needs the target to be using Opera 6.0.3 with Squid 2.4 configured as a proxy. The vulnerability exists primarily due to insufficient input validation and error handling within the SSL/TLS certificate processing components. Organizations should prioritize updating to newer versions of Opera that have proper certificate validation handling, while also ensuring that proxy configurations are properly secured to prevent exploitation of such certificate handling flaws.
Mitigation strategies for this vulnerability include immediate upgrading of Opera browser to versions that properly handle certificate validation, implementing proper certificate pinning policies where applicable, and configuring proxy servers with additional certificate validation controls. Network administrators should also consider implementing certificate monitoring systems that can detect and alert on unusual certificate presentations. The vulnerability serves as a reminder of the importance of proper certificate validation handling in web browsers and the critical need for robust error handling in cryptographic operations. Organizations should also implement regular security assessments of their browser configurations to identify similar certificate handling issues that could lead to service disruption or potential exploitation.