CVE-2008-4063 in Linux
Summary
by MITRE
Multiple unspecified vulnerabilities in Mozilla Firefox 3.x before 3.0.2 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to the layout engine and (1) a zero value of the "this" variable in the nsContentList::Item function; (2) interaction of the indic IME extension, a Hindi language selection, and the "g" character; and (3) interaction of the nsFrameList::SortByContentOrder function with a certain insufficient protection of inline frames.
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Analysis
by VulDB Data Team • 08/17/2019
The vulnerability described in CVE-2008-4063 represents a critical security flaw affecting Mozilla Firefox 3.x versions prior to 3.0.2, specifically targeting the browser's layout engine components. This issue encompasses multiple distinct attack vectors that collectively demonstrate the complexity and severity of memory corruption vulnerabilities in web browser implementations. The vulnerabilities are classified as unspecified but are known to create conditions that can result in either denial of service through memory corruption and application crashes, or potentially more severe arbitrary code execution capabilities that could compromise user systems.
The technical exploitation of these vulnerabilities occurs through specific interactions within Firefox's internal rendering engine. The first vector involves a zero value of the "this" variable within the nsContentList::Item function, which represents a classic null pointer dereference scenario that can lead to memory corruption. This type of flaw falls under CWE-476 which specifically addresses null pointer dereference conditions. The second vulnerability manifests through the interaction between the indic IME extension, Hindi language selection, and the "g" character, indicating a complex interaction between input handling, language processing, and memory management that could be exploited through carefully crafted text input scenarios. The third vector involves the nsFrameList::SortByContentOrder function combined with insufficient protection of inline frames, suggesting a memory management issue during frame sorting operations that could lead to heap corruption.
These vulnerabilities represent significant operational risks for Firefox users, as they could be exploited remotely through web content without requiring user interaction beyond visiting malicious websites. The potential for denial of service means that attackers could repeatedly crash browser sessions, disrupting user productivity and potentially creating persistent availability issues. More concerning is the possibility of arbitrary code execution, which would allow attackers to gain complete control over affected systems, execute malicious code, and potentially establish persistent backdoors. The attack surface is particularly broad given that these vulnerabilities affect core layout engine components that are essential for rendering all web content.
The exploitation of these vulnerabilities aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to privilege escalation and defense evasion through application layer attacks. The memory corruption aspects of these vulnerabilities could be leveraged for privilege escalation attacks, while the denial of service capabilities might be used as part of broader attack campaigns to disable security controls or create conditions for more sophisticated exploitation attempts. Organizations should prioritize immediate patching of affected Firefox installations, as these vulnerabilities were not limited to specific use cases but could be triggered through normal web browsing activities. The remediation strategy should include comprehensive browser updates, along with monitoring for any signs of exploitation attempts, particularly in environments where users may be exposed to untrusted web content. Additionally, implementing network-based protections such as web application firewalls and content filtering systems can provide additional layers of defense against exploitation attempts targeting these specific memory corruption vulnerabilities.
The broader implications of this vulnerability highlight the ongoing challenges in securing complex web browser environments where multiple subsystems must interact seamlessly while maintaining security boundaries. These issues demonstrate how seemingly minor implementation details in core browser components can create significant security risks that affect millions of users globally. The complexity of modern browser architectures means that vulnerabilities like those described in CVE-2008-4063 often require extensive analysis and testing to fully understand their exploitation potential and develop effective mitigations. Security professionals should consider these vulnerabilities as examples of why continuous security testing and rapid patch management are essential components of any comprehensive cybersecurity program.