CVE-2011-0071 in Firefox
Summary
by MITRE
Directory traversal vulnerability in Mozilla Firefox before 3.5.19 and 3.6.x before 3.6.17, Thunderbird before 3.1.10, and SeaMonkey before 2.0.14 on Windows allows remote attackers to determine the existence of arbitrary files, and possibly load resources, via vectors involving a resource: URL.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 11/06/2021
This vulnerability represents a directory traversal issue affecting multiple Mozilla products including Firefox, Thunderbird, and SeaMonkey on Windows platforms. The flaw exists in the handling of resource: URLs and allows remote attackers to perform unauthorized file system operations. The vulnerability specifically impacts versions prior to Firefox 3.5.19 and 3.6.x before 3.6.17, Thunderbird 3.1.10, and SeaMonkey 2.0.14, creating a significant security risk for users operating these older software versions.
The technical implementation of this vulnerability stems from insufficient validation of resource: URLs within the browser's security model. When processing these URLs, the affected applications fail to properly sanitize input parameters that could contain directory traversal sequences such as ../ or ..\.. This weakness enables attackers to craft malicious URLs that can traverse the file system hierarchy and access files that should remain protected. The vulnerability operates at the application layer and leverages the browser's resource loading mechanisms to bypass normal file system access controls.
The operational impact of this vulnerability extends beyond simple file enumeration to potentially enable more serious attacks. Attackers can determine the existence of arbitrary files on the target system, which provides valuable reconnaissance information for further exploitation attempts. In some cases, the vulnerability may allow attackers to load and execute resources from unexpected locations, potentially leading to code execution or information disclosure. This capability significantly undermines the security boundaries that browsers typically maintain between user applications and the underlying operating system.
This vulnerability aligns with CWE-22, which specifically addresses directory traversal or path traversal flaws in software applications. The weakness demonstrates how improper input validation can create security holes that allow attackers to access restricted resources. From an attack framework perspective, this vulnerability maps to multiple ATT&CK techniques including T1059 for command and script injection, and T1566 for social engineering through malicious links. The attack surface is particularly concerning because it affects widely used email and web browsing applications, making it a prime target for phishing campaigns and drive-by downloads.
Organizations and users should immediately update to the patched versions of affected software to remediate this vulnerability. The security patches implemented in versions 3.5.19, 3.6.17, 3.1.10, and 2.0.14 respectively address the root cause by implementing proper input validation for resource: URLs and strengthening the browser's resource loading security model. System administrators should conduct comprehensive inventory checks to identify all affected systems and ensure timely patch deployment across all endpoints. Additionally, network monitoring should be enhanced to detect suspicious resource: URL patterns that could indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date software security patches and implementing defense-in-depth strategies to protect against similar traversal attacks.