CVE-2012-6276 in TL-WR841N
Summary
by MITRE
Directory traversal vulnerability in the web-based management interface on the TP-LINK TL-WR841N router with firmware 3.13.9 build 120201 Rel.54965n and earlier allows remote attackers to read arbitrary files via the URL parameter.
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Analysis
by VulDB Data Team • 08/22/2024
The CVE-2012-6276 vulnerability represents a critical directory traversal flaw within the web management interface of TP-LINK TL-WR841N routers running firmware versions up to and including 3.13.9 build 120202 Rel.54965n. This vulnerability resides in the router's web server implementation and specifically affects how the system processes URL parameters containing directory traversal sequences. The flaw enables unauthenticated remote attackers to access arbitrary files on the device's file system by manipulating the URL parameter in their requests. The vulnerability stems from insufficient input validation and sanitization within the web interface's file handling mechanisms, allowing attackers to navigate beyond the intended directory structure and retrieve sensitive information from the device's storage.
The technical implementation of this vulnerability falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as directory traversal or path traversal attacks. This weakness occurs when web applications fail to properly validate user-supplied input that contains path separators or directory traversal sequences such as "../" or "..\". The TP-LINK router's web interface does not adequately sanitize URL parameters before processing them, allowing an attacker to craft malicious requests that can traverse the file system hierarchy and access files that should remain restricted. The vulnerability is particularly dangerous because it allows access to configuration files, system logs, and potentially sensitive credentials stored within the router's file system.
The operational impact of CVE-2012-6276 extends beyond simple information disclosure, as it provides attackers with potential access to critical system components that could lead to further exploitation. Attackers can retrieve configuration files that may contain administrative credentials, network settings, and other sensitive information that could be used for privilege escalation or additional attacks. The vulnerability affects the router's management interface, which typically requires authentication for administrative functions, but the directory traversal allows attackers to bypass authentication mechanisms by accessing the configuration files directly. This creates a significant risk for network security as compromised routers can serve as entry points for broader network infiltration, potentially enabling attackers to monitor network traffic, redirect requests, or establish persistent access to the local network.
Mitigation strategies for this vulnerability require immediate firmware updates from TP-LINK to address the directory traversal flaw in the web interface. Organizations should ensure all affected TP-LINK TL-WR841N devices are updated to firmware versions that properly sanitize URL parameters and implement proper input validation. Network administrators should also consider implementing network segmentation and access controls to limit exposure of these devices to untrusted networks. Additional defensive measures include disabling the web management interface when not actively needed, restricting access to management interfaces through firewall rules, and monitoring network traffic for suspicious URL patterns. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in embedded device security, aligning with ATT&CK techniques that involve credential access and privilege escalation through exploitation of software vulnerabilities. Organizations should also conduct regular security assessments of network infrastructure to identify and remediate similar vulnerabilities in other network devices and embedded systems.