CVE-2026-84730 in ASUS
Summary
by MITRE • 11/04/2026
Stack-based buffer overflow in certain ASUS Router firmware allows an unauthenticated nearby attacker to execute arbitrary commands with root privileges via a crafted device name. Refer to the ' Security Update for ASUS Router AiCloud Feature ' section on the ASUS Security Advisory for more information.
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Analysis
by VulDB Data Team • 11/04/2026
The vulnerability described constitutes a critical stack-based buffer overflow within specific firmware versions of ASUS routers, specifically affecting components related to network identification and configuration handling. This flaw arises from improper bounds checking when processing device name inputs, allowing an attacker with local network access or proximity to inject maliciously crafted data that exceeds the allocated memory space on the call stack. The technical mechanism involves overwriting adjacent memory locations, including return addresses or function pointers, which enables the execution of arbitrary code under the context of the compromised process. Given that router firmware often runs with elevated privileges, this exploitation results in full root-level control over the device, effectively compromising the integrity and confidentiality of all traffic passing through it.
From a technical perspective, stack-based buffer overflow vulnerabilities are classified under CWE-121: Stack-based Buffer Overflow according to common weakness enumeration standards. The attack vector is particularly dangerous because it does not require authentication, aligning with ATT&CK technique T1078: Valid Accounts or potentially T1190: Exploit Public-Facing Application if the service is exposed externally, though proximity suggests a local network exploitation scenario often categorized under lateral movement or initial access depending on the specific entry point. The attacker crafts a device name string that contains shellcode and padding to overwrite critical stack memory structures. When the vulnerable function returns, it jumps to the injected code rather than its original destination, granting the attacker immediate command execution capabilities with root privileges.
The operational impact of this vulnerability is severe, as it allows an unauthenticated nearby attacker to take complete control of the router. This compromise can lead to a wide range of malicious activities including DNS hijacking, man-in-the-middle attacks on local network traffic, interception of sensitive credentials and personal data transmitted over the network, and using the compromised device as a pivot point for further attacks against other devices on the internal LAN. Additionally, the attacker may install persistent backdoors or botnet agents, turning the router into part of a larger distributed denial-of-service (DDoS) infrastructure. The lack of authentication requirement makes this vulnerability highly exploitable in environments where wireless networks are open or have weak security configurations, significantly expanding the potential attack surface to any device within radio range.
Mitigation strategies must focus on immediate patching and network hardening. Users should update their ASUS router firmware to the latest version provided by Asus, which addresses the buffer overflow issue through improved input validation and memory management practices. In cases where updating is not immediately feasible, isolating critical devices from the general wireless network using VLANs or guest networks can limit exposure. Furthermore, disabling remote administration features if they are not strictly necessary reduces the risk of external exploitation vectors that might compound this local vulnerability. Security monitoring tools should be configured to detect anomalous traffic patterns indicative of buffer overflow attempts or unauthorized command executions on the router interface. Long-term resilience requires adopting a zero-trust architecture for IoT devices and regularly auditing firmware versions across all network infrastructure components to ensure timely application of security patches released by vendors.