CVE-2025-45042 in AC9
Summary
by MITRE • 05/05/2025
Tenda AC9 v15.03.05.14 was discovered to contain a command injection vulnerability via the Telnet function.
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Analysis
by VulDB Data Team • 05/26/2025
The vulnerability identified as CVE-2025-45042 affects the Tenda AC9 router model running firmware version v15.03.05.14 and represents a critical command injection flaw within the device's Telnet functionality. This vulnerability resides in the router's handling of user-supplied input through the Telnet interface, creating a pathway for malicious actors to execute arbitrary commands on the affected device. The flaw stems from inadequate input validation and sanitization mechanisms within the Telnet service implementation, allowing attackers to inject malicious commands that are then processed by the underlying operating system. Such vulnerabilities are particularly dangerous in network infrastructure devices as they can provide attackers with direct access to the router's command execution environment, potentially enabling full system compromise.
The technical exploitation of this vulnerability follows the established patterns of command injection attacks as categorized under CWE-77. The flaw occurs when user input from Telnet sessions is directly concatenated into system commands without proper sanitization or escaping mechanisms. Attackers can leverage this by crafting malicious Telnet commands that include shell metacharacters or command separators, which then get executed by the router's operating system. This type of vulnerability aligns with the ATT&CK framework's technique T1059.001 for Command and Scripting Interpreter, specifically targeting the use of shell commands for execution. The vulnerability essentially allows an attacker to bypass authentication mechanisms and gain unauthorized access to the router's underlying operating system, potentially enabling privilege escalation and persistent access to the network infrastructure.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it can lead to complete network compromise and persistent backdoor access. Once exploited, attackers can modify router configurations, redirect network traffic, establish persistent access points, or use the compromised device as a launching point for further attacks within the network. The Telnet service typically provides administrative access to network devices, making this vulnerability particularly dangerous as it can be exploited by remote attackers without requiring physical access or complex authentication bypasses. The router's firmware version v15.03.05.14 indicates this is likely a legacy vulnerability that has not been patched, as modern firmware versions would typically include proper input validation and sanitization measures to prevent such injection attacks.
Mitigation strategies for CVE-2025-45042 should focus on immediate firmware updates from Tenda to address the command injection vulnerability in the Telnet implementation. Network administrators should disable Telnet services entirely and rely on more secure remote access methods such as SSH for administrative access to network devices. The implementation of network segmentation and access control lists can help limit the potential impact of exploitation by restricting access to critical network infrastructure. Additionally, regular security assessments and network monitoring should be implemented to detect anomalous Telnet activity or unauthorized access attempts. Organizations should also consider implementing network intrusion detection systems that can identify command injection patterns and alert security teams to potential exploitation attempts. The vulnerability serves as a reminder of the importance of secure coding practices in network infrastructure devices and the necessity of regular security updates to address known command injection vulnerabilities.