CVE-2017-5891 in RT-AC
Summary
by MITRE
ASUS RT-AC* and RT-N* devices with firmware before 3.0.0.4.380.7378 have Login Page CSRF and Save Settings CSRF.
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Analysis
by VulDB Data Team • 09/26/2020
The vulnerability identified as CVE-2017-5891 affects ASUS RT-AC and RT-N router models running firmware versions prior to 3.0.0.4.380.7378, representing a critical cross-site request forgery issue that compromises the security of network devices. This flaw resides within the web-based administrative interfaces of these routers, specifically targeting the login page and settings save functionality. The vulnerability stems from the absence of proper anti-CSRF mechanisms in the affected firmware implementations, allowing attackers to execute unauthorized administrative actions through malicious web pages or crafted requests.
The technical nature of this vulnerability aligns with CWE-352, which defines Cross-Site Request Forgery as a security weakness that enables attackers to trick authenticated users into performing unintended actions on web applications they are currently logged into. In the context of network routers, this means an attacker could potentially modify router settings, change administrator credentials, or disable security features without the legitimate user's knowledge or consent. The CSRF protection mechanisms that should normally validate the authenticity of requests originating from the legitimate user's browser are either completely missing or inadequately implemented in the affected ASUS devices.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with persistent administrative control over network infrastructure. Once exploited, an attacker could modify firewall rules, redirect traffic, install malicious firmware, or even create backdoors for continued access. This represents a significant threat to network security since routers serve as the primary gateway for network traffic and often contain sensitive configuration data. The vulnerability affects a wide range of ASUS router models, making it particularly dangerous as it could compromise numerous network endpoints simultaneously.
This vulnerability falls under the ATT&CK framework's technique T1072, which involves the use of remote services for persistence and lateral movement. The exploitation of CSRF vulnerabilities in network devices allows adversaries to maintain persistent access and potentially escalate privileges within the network. Organizations should consider implementing network segmentation and monitoring for unusual traffic patterns that might indicate router compromise. The recommended mitigation strategy involves upgrading to firmware version 3.0.0.4.380.7378 or later, which includes proper CSRF token implementation and validation mechanisms. Network administrators should also consider disabling remote administration features when not required and implementing additional security measures such as network access control and regular security audits to detect potential exploitation attempts.