CVE-2018-25317 in W3002R
Summary
by MITRE • 04/30/2026
Tenda W3002R/A302/W309R wireless routers version V5.07.64_en contain a cookie session weakness vulnerability that allows unauthenticated attackers to modify DNS settings by exploiting insufficient session validation. Attackers can send GET requests to the /goform/AdvSetDns endpoint with a crafted admin language cookie to change primary and secondary DNS servers, redirecting user traffic to malicious DNS servers.
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Analysis
by VulDB Data Team • 05/22/2026
This vulnerability resides in Tenda wireless routers including models W3002R/A302/W309R running firmware version V5.07.64_en, representing a critical session management flaw that undermines the device's security posture. The weakness manifests as an insufficient session validation mechanism within the router's web interface authentication system, specifically affecting the /goform/AdvSetDns endpoint that handles DNS configuration modifications. The vulnerability stems from the router's failure to properly validate administrative privileges when processing requests to modify DNS settings, allowing any unauthenticated attacker to manipulate the device's network configuration through crafted HTTP GET requests.
The technical exploitation of this vulnerability involves crafting a malicious HTTP request that includes a specially formatted admin language cookie, which bypasses the normal authentication checks required for administrative operations. This cookie manipulation technique leverages a fundamental flaw in the router's session handling logic, where the system does not adequately verify that the requesting user possesses legitimate administrative credentials before permitting DNS configuration changes. The vulnerability specifically targets the Advanced DNS Settings functionality, enabling attackers to modify both primary and secondary DNS server addresses, which can redirect all network traffic through malicious DNS servers controlled by the attacker.
The operational impact of this vulnerability extends beyond simple network disruption to encompass full traffic interception and man-in-the-middle attack capabilities. When successful, attackers can redirect all DNS queries from connected devices to malicious servers, enabling them to perform various malicious activities including phishing attacks, malware distribution, and comprehensive network traffic monitoring. This vulnerability effectively allows attackers to compromise the entire local network's DNS resolution process, potentially affecting all devices connected to the router, including smartphones, laptops, and IoT devices that rely on proper DNS resolution for internet connectivity. The implications are particularly severe because DNS manipulation can be used to silently redirect users to fraudulent websites, steal sensitive information, or deliver malicious payloads without users' knowledge.
This vulnerability maps directly to CWE-384, which addresses session management flaws in web applications, and aligns with ATT&CK technique T1071.004 for application layer protocol manipulation. The weakness represents a classic case of insufficient session validation where the router's authentication system fails to properly enforce administrative privileges, creating a path for privilege escalation through session manipulation. Security professionals should note that this vulnerability demonstrates the critical importance of proper authentication checks in network device management interfaces, as it allows attackers to perform administrative functions without legitimate credentials. The impact is amplified by the fact that these routers are commonly deployed in residential and small office environments where network security awareness may be limited, making such attacks more likely to succeed in real-world scenarios.
Mitigation strategies should include immediate firmware updates from Tenda to address the session validation weakness, implementing network segmentation to limit exposure, and monitoring network traffic for suspicious DNS modification patterns. Organizations should also consider disabling remote management features when not required, implementing strong authentication for local administrative access, and deploying network monitoring solutions that can detect unauthorized DNS configuration changes. The vulnerability highlights the necessity of robust session management practices in embedded network devices and underscores the importance of regular security assessments for IoT and networking equipment. Additionally, network administrators should implement proper access controls and regularly audit router configurations to prevent unauthorized modifications, as this vulnerability can be exploited by attackers with minimal technical expertise.