CVE-2007-3073 in Firefox
Summary
by MITRE
Directory traversal vulnerability in Mozilla Firefox 2.0.0.4 and earlier on Mac OS X and Unix allows remote attackers to read arbitrary files via ..%2F (dot dot encoded slash) sequences in a resource:// URI.
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Analysis
by VulDB Data Team • 07/20/2019
The vulnerability described in CVE-2007-3073 represents a critical directory traversal flaw affecting Mozilla Firefox versions 2.0.0.4 and earlier on Mac OS X and Unix operating systems. This security weakness stems from insufficient input validation within the browser's handling of resource URIs, specifically when processing encoded dot-dot-slash sequences. The flaw enables malicious actors to exploit the browser's URI parsing mechanism by crafting specially formatted URLs containing ..%2F sequences that should be properly sanitized but instead allow unauthorized access to the underlying file system.
The technical implementation of this vulnerability occurs at the application layer where Firefox fails to adequately sanitize URI components before resolving file paths. When a resource:// URI containing encoded directory traversal sequences is processed, the browser's internal path resolution logic does not properly validate or normalize the path components, allowing attackers to navigate outside the intended directory boundaries. This misconfiguration creates a path traversal condition that can be exploited to access files that should remain protected within the system's file hierarchy.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the ability to read arbitrary files from the target system. This capability can lead to sensitive data exposure including configuration files, user credentials, system logs, and other confidential information stored within the application's directory structure. The vulnerability is particularly concerning in environments where Firefox serves as the primary web browser and users may encounter malicious websites or be tricked into visiting compromised web pages that exploit this flaw.
Security professionals should note that this vulnerability aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw also maps to several ATT&CK techniques including T1059 for command and scripting interpreter and T1566 for phishing, as attackers can leverage this vulnerability to gain unauthorized access to sensitive system information. The attack surface is significantly expanded when considering that the vulnerability affects multiple operating systems, making it a widespread concern for organizations using these older Firefox versions.
Mitigation strategies for CVE-2007-3073 should prioritize immediate patching of affected Firefox installations to version 2.0.0.5 or later, which contains the necessary fixes to properly sanitize URI components. Organizations should also implement network-level controls including web application firewalls and proxy servers that can detect and block suspicious URI patterns containing encoded directory traversal sequences. Additional defensive measures include restricting browser privileges, implementing strict access controls on system files, and conducting regular security assessments to identify potential exploitation vectors. System administrators should also consider deploying intrusion detection systems that can monitor for anomalous file access patterns that may indicate exploitation attempts against this vulnerability.