CVE-2004-0648 in Firefox
Summary
by MITRE
Mozilla (Suite) before 1.7.1, Firefox before 0.9.2, and Thunderbird before 0.7.2 allow remote attackers to launch arbitrary programs via a URI referencing the shell: protocol.
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Analysis
by VulDB Data Team • 09/27/2025
This vulnerability exists in Mozilla Suite versions prior to 1.7.1, Firefox versions prior to 0.9.2, and Thunderbird versions prior to 0.7.2, representing a critical security flaw that allows remote attackers to execute arbitrary programs on affected systems. The vulnerability specifically relates to improper handling of the shell: URI protocol which enables attackers to craft malicious web pages or email content that, when viewed by a victim using an affected browser or email client, automatically launches programs on the victim's system. The technical implementation flaw occurs in how these applications parse and process URI schemes, particularly the shell: protocol which is designed to launch external applications but lacks proper validation and sanitization of the target parameters. This weakness falls under CWE-78, which describes improper neutralization of special elements used in OS command injection attacks, and specifically relates to command injection vulnerabilities where user-controllable input is directly passed to system execution functions without adequate sanitization. The operational impact of this vulnerability is severe as it allows for arbitrary code execution with the privileges of the user running the affected application, potentially enabling attackers to install malware, steal sensitive information, or take complete control of the affected system. Attackers can craft malicious links that, when clicked by a victim, automatically execute programs such as launching calculators, opening web browsers, or even executing malicious executables stored on remote servers. The vulnerability is particularly dangerous in phishing attacks where attackers can embed these malicious shell: protocol references in emails or web pages, making it difficult for users to distinguish between legitimate and malicious content. From an attack perspective, this vulnerability aligns with the MITRE ATT&CK framework under technique T1059.007 for command and scripting interpreter, specifically focusing on the use of shell commands to execute malicious payloads. The risk is elevated because the affected applications are widely used, and the exploitation requires minimal user interaction beyond simply viewing the malicious content. Organizations using these vulnerable versions should immediately implement mitigations including updating to patched versions of the software, implementing network-level restrictions on shell: protocol handling, and educating users about the dangers of clicking untrusted links. The patch for this vulnerability involved implementing proper input validation and sanitization for URI protocols, ensuring that shell: protocol references are properly escaped and validated before any execution occurs. Security administrators should also consider deploying web application firewalls and content filtering solutions to prevent malicious shell: protocol references from reaching end users, particularly in enterprise environments where automated patching may not be immediate. The vulnerability demonstrates the critical importance of proper URI handling and input validation in preventing command injection attacks, and serves as a reminder of the need for comprehensive security testing of protocol handlers in web browsers and email clients.