CVE-2017-6548 in RT-AC53
Summary
by MITRE
Buffer overflows in networkmap in ASUS ASUSWRT on RT-AC53 3.0.0.4.380.6038 devices allow remote attackers to execute arbitrary code on the router via a long host or port in crafted multicast messages.
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Analysis
by VulDB Data Team • 08/15/2024
The vulnerability identified as CVE-2017-6548 represents a critical buffer overflow flaw within the networkmap component of ASUS ASUSWRT firmware versions prior to 3.0.0.4.380.6038 specifically affecting RT-AC53 devices. This issue resides in the handling of multicast messages and demonstrates a classic stack-based buffer overflow vulnerability that can be exploited remotely. The flaw occurs when the system processes host or port information contained within crafted multicast packets, where insufficient input validation allows attackers to overflow memory buffers and potentially overwrite critical program execution data.
The technical implementation of this vulnerability stems from improper bounds checking within the networkmap functionality that processes network discovery protocols. When multicast messages containing excessively long host or port parameters are received, the firmware fails to validate the length of these inputs before copying them into fixed-size buffers. This condition creates an exploitable memory corruption scenario that aligns with CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability specifically affects the router's ability to process network discovery messages and can be triggered through the network interface without requiring authentication or physical access to the device.
The operational impact of this vulnerability extends beyond simple remote code execution capabilities to encompass complete system compromise and persistent access to the affected network infrastructure. Attackers can leverage this vulnerability to gain unauthorized access to the router's administrative functions, potentially enabling them to modify network configurations, redirect traffic, or establish persistent backdoors within the network. The remote nature of the exploit means that attackers can target vulnerable devices from anywhere on the internet, making this vulnerability particularly dangerous for organizations relying on ASUS routers for their network infrastructure. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1059 for command and script interpreter and T1068 for exploit for privilege escalation.
Mitigation strategies for CVE-2017-6548 should prioritize immediate firmware updates from ASUS to the latest available versions that contain patches addressing the buffer overflow conditions. Network administrators should implement network segmentation and access control measures to limit exposure of vulnerable devices to untrusted networks, particularly ensuring that multicast traffic is properly filtered at network boundaries. Additional protective measures include monitoring network traffic for unusual multicast activity patterns that might indicate exploitation attempts, implementing intrusion detection systems with signatures specific to this vulnerability, and maintaining comprehensive network documentation to track all connected devices. Organizations should also consider disabling unnecessary multicast services on affected routers and regularly auditing their network infrastructure to identify and remediate similar vulnerabilities in other network equipment. The vulnerability demonstrates the importance of proper input validation and memory management practices in embedded network devices, aligning with security best practices outlined in NIST SP 800-144 and OWASP Top 10 security guidelines for network infrastructure protection.