CVE-2025-45491

Comprehensive Technical Analysis of CVE-2025-45491

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-45491 Description: The Linksys E5600 v1.1.0.26 firmware contains a command injection vulnerability in the runtime.ddnsStatus DynDNS function via the username parameter. CVSS Score: 9.8 (Critical)

Severity Evaluation:

• CVSS Base Score: 9.8
• Impact Sub-Score: 5.9
• Exploitability Sub-Score: 3.9

The high CVSS score indicates a critical vulnerability that can be easily exploited with severe consequences. The vulnerability allows an attacker to inject arbitrary commands into the system, leading to potential full system compromise.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Network-Based Attack: An attacker can exploit this vulnerability remotely by sending crafted requests to the affected device.
• Local Attack: An attacker with local network access can also exploit this vulnerability.

Exploitation Methods:

• Command Injection: By manipulating the username parameter in the runtime.ddnsStatus function, an attacker can inject malicious commands.
• Payload Delivery: The injected commands can be used to execute arbitrary code, download and execute malware, or exfiltrate sensitive data.

Example Exploit:

import requests

url = "http://<target_ip>/runtime.ddnsStatus"
payload = {'username': '; <malicious_command>;'}

response = requests.post(url, data=payload)
print(response.text)

3. Affected Systems and Software Versions

Affected Systems:

• Linksys E5600 routers running firmware version 1.1.0.26.

Software Versions:

• Firmware version 1.1.0.26 is specifically affected. Other versions may also be vulnerable but have not been explicitly tested.

4. Recommended Mitigation Strategies

Immediate Mitigation:

• Firmware Update: Upgrade to the latest firmware version provided by Linksys.
• Network Segmentation: Isolate the affected device from critical network segments.
• Firewall Rules: Implement strict firewall rules to limit access to the device.

Long-Term Mitigation:

• Regular Patching: Ensure that all network devices are regularly updated with the latest security patches.
• Intrusion Detection Systems (IDS): Deploy IDS to monitor for suspicious activity.
• Access Control: Implement strong access control measures to limit administrative access to the device.

5. Impact on Cybersecurity Landscape

Broader Implications:

• IoT Security: This vulnerability highlights the ongoing challenges in securing Internet of Things (IoT) devices, which are often deployed with outdated or vulnerable firmware.
• Supply Chain Risks: Vulnerabilities in consumer-grade devices can have cascading effects on enterprise networks, emphasizing the need for robust supply chain security.
• Remote Exploitation: The ability to exploit this vulnerability remotely underscores the importance of securing network-connected devices against external threats.

6. Technical Details for Security Professionals

Vulnerability Details:

• Function Affected: runtime.ddnsStatus
• Parameter: username
• Vulnerability Type: Command Injection

Exploit Code Analysis:

• The username parameter is not properly sanitized, allowing an attacker to inject commands.
• The injected commands are executed with the privileges of the running process, potentially leading to full system compromise.

Detection and Response:

• Log Analysis: Monitor logs for unusual command execution or unexpected network traffic.
• Behavioral Analysis: Use behavioral analysis tools to detect anomalous activity indicative of command injection.
• Incident Response: Develop an incident response plan that includes steps for isolating affected devices, containing the threat, and remediating the vulnerability.

References:

• Exploit Code
• Technical Documentation

Conclusion

CVE-2025-45491 represents a critical vulnerability in the Linksys E5600 router firmware that can be exploited to execute arbitrary commands. Organizations should prioritize updating affected devices and implementing robust security measures to mitigate the risk. This vulnerability underscores the importance of proactive security management in the IoT ecosystem.