CVE-2013-3516 in WNR3500U
Summary
by MITRE
NETGEAR WNR3500U and WNR3500L routers uses form tokens abased solely on router's current date and time, which allows attackers to guess the CSRF tokens.
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Analysis
by VulDB Data Team • 02/13/2024
The vulnerability identified as CVE-2013-3516 affects NETGEAR WNR3500U and WNR3500L wireless routers, representing a critical weakness in the implementation of Cross-Site Request Forgery protection mechanisms. This flaw stems from the routers' use of form tokens that are generated based exclusively on the device's current date and time, creating a predictable and insufficiently random security measure. The vulnerability falls under the category of weak cryptographic randomness and improper session management, which are commonly associated with CWE-310 and CWE-306. The predictable nature of these tokens makes them susceptible to brute force attacks and automated exploitation attempts.
The technical implementation of CSRF protection in these routers demonstrates a fundamental misunderstanding of security requirements for session tokens. By relying solely on timestamp-based generation without incorporating sufficient entropy or randomization factors, the system creates tokens that can be easily guessed or reconstructed by attackers who have access to the network or can observe the token generation process. This weakness allows malicious actors to craft forged requests that appear legitimate to the router's security mechanisms, effectively bypassing the CSRF protection entirely. The attack vector typically involves an attacker monitoring network traffic to capture valid CSRF tokens, then using the predictable pattern to generate new tokens that can be used to perform unauthorized administrative actions on the router.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete administrative control over the affected routers. This access enables malicious actors to modify network configurations, change administrator credentials, disable security features, and potentially establish persistent backdoors within the network infrastructure. The vulnerability affects not only the router's own security posture but also compromises the entire network ecosystem that relies on the router's configuration for proper operation. Network administrators face significant risks including data interception, man-in-the-middle attacks, and complete network compromise, as the router becomes a potential entry point for broader attacks. This vulnerability is particularly concerning in enterprise environments where these devices may be deployed without proper security hardening or regular firmware updates.
The mitigation strategies for this vulnerability require immediate firmware updates from NETGEAR to implement properly randomized CSRF token generation mechanisms that incorporate sufficient entropy and cryptographic randomness. Organizations should also implement network segmentation to limit access to administrative interfaces, deploy network monitoring solutions to detect suspicious activities, and ensure that all administrative access occurs through secure channels with strong authentication mechanisms. Security professionals should consider implementing additional controls such as IP address restrictions on administrative interfaces and regular security assessments to identify similar weaknesses in other network devices. The vulnerability highlights the importance of following established security frameworks and standards, particularly those addressing session management and CSRF protection as outlined in the OWASP Top Ten and NIST cybersecurity guidelines. Organizations must also ensure proper device lifecycle management to prevent deployment of vulnerable firmware versions and maintain regular update schedules to address known security issues.