CVE-2008-5501 in Firefox
Summary
by MITRE
The layout engine in Mozilla Firefox 3.x before 3.0.5, Thunderbird 2.x before 2.0.0.19, and SeaMonkey 1.x before 1.1.14 allows remote attackers to cause a denial of service via vectors that trigger an assertion failure.
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Analysis
by VulDB Data Team • 08/03/2021
The vulnerability identified as CVE-2008-5501 represents a critical assertion failure flaw within the layout engine of several Mozilla-based applications including Firefox 3.x versions prior to 3.0.5, Thunderbird 2.x versions before 2.0.0.19, and SeaMonkey 1.x versions before 1.1.14. This vulnerability falls under the category of denial of service attacks and is classified as a software fault that can be exploited remotely by malicious actors. The issue stems from improper handling of certain input conditions within the browser engine's rendering capabilities, specifically when processing web content that triggers an assertion failure mechanism.
The technical implementation of this vulnerability involves the layout engine's inability to properly validate or process malformed or specially crafted web content that causes the application to terminate unexpectedly. When an attacker constructs specific web pages or content that triggers this assertion failure, the browser engine encounters an internal inconsistency that results in a crash or complete application termination. This behavior is particularly concerning because it can be triggered through normal web browsing activities, making it an attractive target for exploitation in real-world scenarios. The vulnerability is categorized under CWE-248 as an Uncaught Exception, where the application fails to properly handle exceptional conditions that should be gracefully managed.
From an operational perspective, this vulnerability poses significant risks to end users and organizations relying on these affected software versions. The remote exploitation capability means that users can be compromised simply by visiting malicious websites or opening specially crafted emails in Thunderbird. The denial of service impact can be severe as it completely disrupts user productivity and can be used as a vector for more sophisticated attacks. Security researchers have noted that such assertion failures often serve as stepping stones for attackers to develop more advanced exploits, as they provide insights into the application's internal state and memory management patterns. The vulnerability also aligns with ATT&CK technique T1499.004 for Network Denial of Service, where adversaries can disrupt services by causing application crashes or resource exhaustion.
The mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by Mozilla. Organizations should prioritize upgrading to the patched versions of Firefox 3.0.5, Thunderbird 2.0.0.19, and SeaMonkey 1.1.14 to eliminate the risk of exploitation. Additionally, network administrators can implement web filtering solutions to block access to known malicious domains that might host exploit code targeting this vulnerability. Browser hardening measures such as disabling JavaScript for untrusted sites or implementing content security policies can provide additional layers of protection. Security monitoring should include detection of unusual browser crash patterns or assertion failure logs that might indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining current software versions and implementing robust patch management processes to prevent exploitation of known security flaws that can lead to complete service disruption.