CVE-2026-102815 in RE305
Summary
by MITRE • 10/27/2026
An operating-system command injection vulnerability exists in the tmpServer service of TP-Link RE305 V3. The service runs with root privileges and listens on the local loopback interface. A local attacker with access to a low-privileged process on the device may submit a crafted request to the TDDPv1 service and execute operating-system commands with root privileges.
Successful exploitation may allow a local attacker with low privileges to obtain root privileges and execute arbitrary operating-system commands on the affected device.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified in TP-Link RE305 V3 represents a critical security flaw within the tmpServer service, which is part of the TDDPv1 protocol implementation. This specific component operates with elevated root privileges and binds to the local loopback interface, typically intended to restrict access to processes running on the same host. However, the architectural design fails to adequately validate or sanitize input data received through this interface. Consequently, a local attacker who has gained control over any low-privileged process on the device can interact directly with the tmpServer service. By submitting crafted requests containing malicious payloads, the attacker exploits an operating-system command injection flaw that allows for the execution of arbitrary commands under the context of the root user. This scenario highlights a significant breakdown in privilege separation and input validation mechanisms within embedded IoT firmware components.
From a technical perspective, this vulnerability aligns with CWE-78, which describes Improper Neutralization of Special Elements used in an OS Command (OS Command Injection). The core issue lies in the application's failure to properly sanitize user-supplied data before passing it to system-level command interpreters such as /bin/sh or similar utilities. Because the tmpServer service runs with root privileges, any successful injection results in immediate privilege escalation from a low-privileged context to full administrative control over the device. This is further compounded by the fact that while the service listens on localhost, many IoT devices allow local processes to communicate via Unix domain sockets or TCP loopback without sufficient access controls, effectively bypassing network-based perimeter defenses. The exploitation does not require remote network access but rather physical or logical access to a compromised low-privilege process, which is often achievable through other vulnerabilities such as buffer overflows in web interfaces or insecure default credentials that allow initial foothold acquisition.
The operational impact of this vulnerability is severe, enabling complete compromise of the device's integrity and confidentiality. An attacker can execute arbitrary operating-system commands with root privileges, allowing them to install persistent backdoors, exfiltrate sensitive network configuration data, modify firmware settings, or pivot into other devices on the local network segment. In the context of Internet of Things (IoT) ecosystems, a compromised router often serves as a gateway for lateral movement, potentially exposing internal networks to external threats. The ability to escalate privileges locally means that even if an attacker only has limited access initially, they can quickly gain full control over the system's kernel-level functions and file systems. This undermines the fundamental security principle of least privilege and renders standard isolation mechanisms ineffective against local attackers who have already breached lower-security boundaries within the device environment.
Mitigation strategies for this vulnerability primarily involve vendor-provided firmware updates that patch the input validation logic in the tmpServer service. Until such patches are available, administrators should consider isolating affected devices on separate network segments with strict firewall rules to limit lateral movement opportunities. Additionally, implementing strong access controls and monitoring local process behavior can help detect anomalous activities indicative of exploitation attempts. From a development standpoint, this incident underscores the necessity for rigorous secure coding practices in embedded systems, particularly regarding command injection prevention techniques such as using parameterized commands instead of string concatenation when invoking system utilities. Adhering to industry standards like CWE-78 during design and testing phases can prevent similar flaws from being introduced into future firmware versions. Furthermore, adopting a defense-in-depth approach where services are run with minimal required privileges rather than root access would significantly reduce the impact of such vulnerabilities if they were to be exploited in other contexts.