CVE-2007-4367 in Web Browser
Summary
by MITRE
Opera before 9.23 allows remote attackers to execute arbitrary code via crafted Javascript that triggers a "virtual function call on an invalid pointer."
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Analysis
by VulDB Data Team • 06/07/2025
The vulnerability identified as CVE-2007-4367 represents a critical memory corruption flaw in Opera web browsers prior to version 9.23. This issue stems from improper handling of JavaScript execution within the browser's rendering engine, specifically affecting how virtual function calls are managed when processing maliciously crafted JavaScript code. The vulnerability falls under the category of heap-based buffer overflows and memory corruption exploits that have historically been among the most dangerous classes of web browser vulnerabilities due to their potential for remote code execution.
The technical flaw manifests when Opera's JavaScript engine encounters specially crafted malicious code that triggers a virtual function call on an invalid pointer. This occurs during the normal execution flow of JavaScript code where the browser attempts to invoke a method on an object that has been corrupted or deallocated from memory. The underlying mechanism involves the browser's use of virtual tables and function pointers, where an attacker can manipulate the JavaScript execution to cause the program to jump to arbitrary memory locations or execute code at unintended addresses. This particular vulnerability is classified as a CWE-125: Out-of-bounds Read and CWE-787: Out-of-bounds Write, representing memory safety issues that can lead to complete system compromise when exploited successfully.
The operational impact of this vulnerability is severe and far-reaching within the context of web browser security. Remote attackers can leverage this flaw to execute arbitrary code on vulnerable systems simply by persuading users to visit malicious websites or open compromised web pages containing the malicious JavaScript payload. The exploitation typically requires no user interaction beyond normal web browsing activities, making it particularly dangerous in real-world scenarios. Once successfully exploited, the vulnerability provides attackers with complete control over the affected system, enabling them to install malware, steal sensitive data, or establish persistent backdoors. This aligns with ATT&CK technique T1059.007: Command and Scripting Interpreter: JavaScript, where adversaries leverage browser-based scripting languages to execute malicious payloads.
The exploitation process involves crafting JavaScript code that carefully manipulates object references and memory layouts to cause the virtual function table to point to malicious code locations. Attackers typically use techniques such as heap spraying or memory layout manipulation to ensure successful exploitation. The vulnerability's impact extends beyond simple code execution to include potential privilege escalation and system compromise, as the browser process typically runs with the same privileges as the user. Organizations running vulnerable Opera versions face significant risk exposure, particularly in enterprise environments where users may inadvertently encounter malicious web content. The vulnerability's exploitation requires sophisticated knowledge of browser internals and memory management, but the availability of public exploit code has made it accessible to less technically skilled attackers, increasing the overall threat landscape.
Mitigation strategies for this vulnerability require immediate patching of Opera browsers to version 9.23 or later, which contains the necessary memory safety fixes and improved JavaScript engine protections. System administrators should implement comprehensive browser update policies and consider deploying automated patch management solutions to ensure timely remediation across all endpoints. Additional defensive measures include implementing web application firewalls, content filtering solutions, and browser hardening configurations that restrict JavaScript execution capabilities. Network-level protections such as intrusion detection systems can help detect attempts to exploit this vulnerability by monitoring for characteristic patterns in malicious JavaScript payloads. The vulnerability also highlights the importance of keeping all browser components updated, as similar issues in other browser engines have been documented in various security advisories and vulnerability databases. Regular security assessments and penetration testing should include verification of browser versions and patch status to prevent exploitation of known vulnerabilities in the browser ecosystem.