CVE-2008-2933 in Firefox
Summary
by MITRE
Mozilla Firefox before 2.0.0.16, and 3.x before 3.0.1, interprets | (pipe) characters in a command-line URI as requests to open multiple tabs, which allows remote attackers to access chrome:i URIs, or read arbitrary local files via manipulations involving a series of URIs that is not entirely handled by a vector application, as exploited in conjunction with CVE-2008-2540. NOTE: this issue exists because of an insufficient fix for CVE-2005-2267.
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Analysis
by VulDB Data Team • 04/22/2025
The vulnerability described in CVE-2008-2933 represents a significant security flaw in Mozilla Firefox versions prior to 2.0.0.16 and 3.x before 3.0.1, where the browser incorrectly processes pipe characters in command-line URIs. This issue stems from an inadequate handling of URI parsing logic that fails to properly sanitize input containing the vertical bar character. The flaw allows remote attackers to exploit a weakness in Firefox's tab opening mechanism by crafting malicious URIs that contain pipe characters, which the browser interprets as commands to open multiple tabs rather than as single URI requests. This misinterpretation creates a pathway for unauthorized access to privileged chrome:i URIs that should normally be restricted to the browser's internal components. The vulnerability is particularly concerning because it enables attackers to bypass normal access controls and potentially read arbitrary local files on the victim's system, representing a serious escalation of privileges.
The technical implementation of this vulnerability involves Firefox's URI handling subsystem where pipe characters are not properly escaped or validated during command-line processing. When a user or application passes a URI containing a pipe character to Firefox, the browser's parser incorrectly splits the URI at the pipe symbol and attempts to process each segment as a separate tab opening request. This behavior creates a vector for exploitation when combined with other vulnerabilities such as CVE-2008-2540, which allows for more sophisticated attack chains. The insufficient fix for the original CVE-2005-2267 vulnerability means that while some aspects of the issue were addressed, the core parsing flaw remained unresolved, allowing attackers to craft sequences of URIs that exploit the incomplete sanitization mechanism. This represents a classic case of security regression where a partial fix introduces new attack surfaces rather than completely resolving the underlying problem.
The operational impact of CVE-2008-2933 extends beyond simple information disclosure to encompass potential complete system compromise. Attackers can leverage this vulnerability to access chrome:i URIs which provide access to Firefox's internal chrome interface and associated functionality that should be restricted to the browser's own components. The ability to read arbitrary local files opens possibilities for sensitive data exfiltration, credential theft, or further exploitation of the victim's system. When combined with other vulnerabilities like CVE-2008-2540, this weakness enables attackers to create sophisticated multi-stage attacks that can bypass standard security controls. The vulnerability affects a wide range of Firefox versions and could be exploited through various vectors including malicious websites, phishing campaigns, or social engineering attacks that trick users into clicking on specially crafted links. The impact is particularly severe because it operates at the application level and can be exploited without requiring any special privileges or system-level access.
Mitigation strategies for CVE-2008-2933 focus primarily on immediate version upgrades to Firefox 2.0.0.16 or 3.0.1 and later, which contain the necessary fixes for the URI parsing vulnerability. Organizations should implement comprehensive patch management processes to ensure all Firefox installations are updated promptly, as this vulnerability was actively exploited in the wild. Network administrators can deploy web filtering solutions that block access to known malicious domains and implement strict content security policies that prevent the execution of potentially dangerous URI sequences. Browser security configurations should be hardened by disabling unnecessary features and restricting access to local file systems through appropriate security policies. The vulnerability aligns with CWE-20 Improper Input Validation and CWE-77 Attack String Manipulation, representing a failure in proper input sanitization and validation. From an ATT&CK framework perspective, this vulnerability maps to T1059 Command and Scripting Interpreter and T1071.004 Application Layer Protocol: Web Protocols, as it exploits command execution through crafted web protocols and URI manipulation. Organizations should also implement monitoring solutions that can detect anomalous URI patterns and tab opening behaviors that might indicate exploitation attempts, while maintaining regular security assessments to identify similar parsing vulnerabilities in other browser components or applications.