CVE-2005-2602 in Firefox
Summary
by MITRE
Mozilla Thunderbird 1.0 and Firefox 1.0.6 allows remote attackers to obfuscate URIs via a long URI, which causes the address bar to go blank and could facilitate phishing attacks.
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Analysis
by VulDB Data Team • 06/30/2025
The vulnerability described in CVE-2005-2602 represents a significant security flaw in Mozilla Thunderbird 1.0 and Firefox 1.0.6 that exploits the handling of excessively long Uniform Resource Identifiers. This issue stems from the browsers' inability to properly process and display URIs that exceed certain length thresholds, creating a potential avenue for malicious actors to craft deceptive web addresses that appear legitimate while concealing harmful destinations. The flaw specifically affects the address bar functionality where extremely long URIs cause the display to become blank or obscured, making it difficult for users to verify the actual destination of a web page.
The technical implementation of this vulnerability involves the browsers' URI parsing and rendering mechanisms failing to handle length constraints appropriately. When a URI exceeds the maximum display capacity of the address bar, the browser's user interface elements become corrupted or obscured, creating a situation where the legitimate address portion of the URL disappears from view. This behavior creates an opportunity for attackers to construct phishing pages using long, legitimate-looking URLs that truncate or obscure the malicious components, effectively masking the true destination of the page. The vulnerability operates at the application layer and directly impacts user trust in the browser's address bar as a security indicator.
The operational impact of this vulnerability is particularly concerning from a phishing attack perspective, as it directly undermines user confidence in the browser's address bar security feature. Attackers can exploit this flaw by crafting long URIs that appear to lead to trusted domains while concealing malicious subdomains or paths in the truncated display. This manipulation creates a false sense of security for users who rely on address bar verification, potentially leading to successful social engineering attacks where victims unknowingly navigate to malicious sites. The vulnerability also affects the browser's ability to properly display security indicators such as SSL certificates, further reducing the user's ability to make informed security decisions. From a cybersecurity perspective, this issue represents a classic case of user interface deception that bypasses traditional security controls.
Mitigation strategies for this vulnerability should focus on implementing proper URI length validation and address bar display mechanisms within the browser's rendering engine. Security measures should include establishing maximum URI length limits that prevent truncation issues, implementing robust display handling for long URIs, and ensuring that security indicators remain visible regardless of URI length. The fix should address the underlying code that handles URI parsing and display, potentially through CWE-120 (Buffer Overflow) remediation techniques and proper input validation. Organizations should also consider implementing additional security measures such as URL reputation checking and user awareness training to complement the technical fixes. This vulnerability aligns with ATT&CK technique T1566.001 (Phishing: Spearphishing Attachment) and demonstrates the importance of secure coding practices in preventing user interface-based attacks that exploit trust relationships.