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CERT Coordination Center

ReadyNet WRT300N-DD Wireless Router contains multiple vulnerabilities

Vulnerability Note VU#167992

Original Release Date: 2015-12-10 | Last Revised: 2015-12-10


ReadyNet WRT300N-DD Wireless Router, firmware version 1.0.26, uses default credentials, is vulnerable to cross-site request forgery, and uses insufficiently random values for DNS queries.


CWE-255: Credentials Management - CVE-2015-7280

The ReadyNet WRT300N-DD Wireless Router web administration interface uses non-random default credentials of admin:admin. A local area network attacker can gain privileged access to a vulnerable device's web management interfaces or leverage default credentials in remote attacks such as cross-site request forgery.

CWE-352: Cross-Site Request Forgery (CSRF) - CVE-2015-7281

The ReadyNet WRT300N-DD contains a global CSRF vulnerability. An attacker can perform actions with the same permissions as a victim user, provided the victim has an active session and is induced to trigger the malicious request. Note that in combination with default credentials, an attacker can establish an active session as part of an attack and therefore would not require a victim to be logged in.

The CVSS score below reflects CVE-2015-7281.

CWE-330: Use of Insufficiently Random Values - CVE-2015-7282

The ReadyNet WRT300N-DD uses static source ports for all DNS queries originating from the local area network (LAN). An attacker with the ability to spoof DNS responses can cause WRT300N-DD LAN clients to contact incorrect or malicious hosts under the attacker's control.

The following graph shows a distribution of 330 DNS queries captured on the WAN port of the WRT300N-DD:


A remote, unauthenticated attacker may be able to spoof DNS responses to cause WRT300N-DD LAN clients to contact attacker-controlled hosts or induce an authenticated user into making an unintentional request to the web server that will be treated as an authentic request. A local area network attacker can take complete control of a device using default admin credentials.


The CERT/CC is currently unaware of a practical solution to this problem. Until these vulnerabilities are addressed, users should consider the following workarounds.

Restrict access and use strong passwords

As a general good security practice, only allow trusted hosts to connect to the LAN. Implement strong passwords for WiFi and for the web management interface. Strong passwords can help to prevent blind guessing attempts that would establish sessions for CSRF attacks. LAN hosts should not browse the Internet while the web management interface has an active session in a browser tab.

Note that there are no practical workarounds for the DNS spoofing vulnerability, as general users are unlikely to be able to monitor traffic entering the router's WAN port.

Vendor Information


ReadyNet Affected

Notified:  September 15, 2015 Updated: December 10, 2015



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

CVSS Metrics

Group Score Vector
Base 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P
Temporal 6.5 E:F/RL:U/RC:C
Environmental 1.6 CDP:ND/TD:L/CR:ND/IR:ND/AR:ND



These vulnerabilities were reported by Joel Land of the CERT/CC.

This document was written by Joel Land.

Other Information

CVE IDs: CVE-2015-7280, CVE-2015-7281, CVE-2015-7282
Date Public: 2015-12-10
Date First Published: 2015-12-10
Date Last Updated: 2015-12-10 17:04 UTC
Document Revision: 18

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