CVE-2018-5767 in AC15
Summary
by MITRE
An issue was discovered on Tenda AC15 V15.03.1.16_multi devices. A remote, unauthenticated attacker can gain remote code execution on the device with a crafted password parameter for the COOKIE header.
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Analysis
by VulDB Data Team • 08/13/2024
The vulnerability identified as CVE-2018-5767 affects Tenda AC15 V15.03.1.16_multi wireless routers, representing a critical remote code execution flaw that can be exploited without authentication. This vulnerability resides in the device's handling of the COOKIE header during authentication processes, specifically when processing a crafted password parameter. The flaw allows an attacker to inject malicious code through a specially crafted HTTP request that manipulates the authentication cookie, potentially enabling complete system compromise.
The technical nature of this vulnerability stems from improper input validation and sanitization within the router's web interface authentication mechanism. When the device processes the COOKIE header containing a malformed password parameter, it fails to properly validate or sanitize the input before using it in subsequent system operations. This classic input validation error creates a path for arbitrary code execution, aligning with CWE-20, which describes improper input validation in software systems. The vulnerability operates at the application layer of the network stack, making it particularly dangerous as it can be exploited over the network without requiring any prior authentication credentials.
From an operational impact perspective, this vulnerability presents a severe risk to network security and device integrity. An unauthenticated attacker can remotely execute arbitrary code on the affected device, potentially gaining full administrative control over the router. This compromise allows for complete network infiltration, including the ability to modify routing tables, intercept network traffic, redirect DNS requests, and establish backdoor access for persistent network monitoring. The attack surface extends beyond the individual device to encompass the entire network infrastructure that relies on the compromised router for connectivity and security policy enforcement.
The exploitation of this vulnerability follows patterns consistent with ATT&CK technique T1059, which involves executing code through command and scripting interpreters. Attackers can leverage this vulnerability to establish persistent access points within the network, potentially using the compromised device as a pivot for attacking internal network resources. Network defenders should consider this vulnerability as part of a broader attack chain that could lead to complete network compromise, particularly in environments where wireless routers serve as primary network gateways. The lack of authentication requirements makes this vulnerability particularly attractive to automated exploitation tools and malicious actors seeking to establish persistent network footholds.
Mitigation strategies should include immediate firmware updates from Tenda to address the input validation flaw, network segmentation to limit access to critical devices, and implementation of network monitoring to detect anomalous cookie header usage patterns. Security teams should also deploy intrusion detection systems capable of identifying suspicious HTTP request patterns and consider disabling unnecessary web management interfaces. Regular security assessments of network infrastructure should include verification of device firmware versions and vulnerability scanning to identify similar unpatched devices throughout the network infrastructure, ensuring comprehensive protection against similar exploitation vectors.