Vulnerability Note VU#939260
ZyXEL Wireless N300 NetUSB Router NBG-419N devices contain multiple vulnerabilities
Original Release date: 11 Apr 2014 | Last revised: 16 Apr 2014

Overview
ZyXEL Wireless N300 NetUSB Router NBG-419N running firmware version 1.00(BFQ.6)C0, and possibly earlier versions, is susceptible to multiple vulnerabilities. Other device models that use similar firmware may also be vulnerable.

Description
ZyXEL Wireless N300 NetUSB Router NBG-419N running firmware version 1.00(BFQ.6)C0, and possibly earlier versions, has been reported to contain multiple vulnerabilities.
CWE-425: Direct Request – CVE-2014-0353
Authentication for content located in any subdirectory of the web root may be bypassed by escaping the "/" characters in the URL. For example, curl -v "http://<deviceip>/local%2Fadvance%2Fwlan.asp"

CWE-259: Use of Hard-coded PasswordCVE-2014-0354
A hard-coded password of qweasdzxc may be used to login to the index.asp page.

CWE-121: Stack-based Buffer Overflow – CVE-2014-0355
The checkWeather function is vulnerable to a buffer overflow when parsing the forecastrss xml file provided from hxxp://weather.yahooapis.com/forecastrss. The vulnerability may be triggered with the following XML content: <yweather:condition  text="Partly Cloudy"  code="47"  temp="<overflow data goes here>". An attacker would need a man-in-the middle vantage point to exploit this vulnerability and the user would need to access index.asp in a web browser to trigger the download.

The detectWeather function is vulnerable to a buffer overflow of the WeatherCity and WeatherDegree variables.

The UpnpAddRunRLQoS(), UpnpDeleteRunRLQoS(), and UpnpDeletePortCheckType() functions are reported to be vulnerable to a buffer overflow vulnerability.

The udps command SET COUNTRY is reported to be vulnerable to command injection and a buffer overflow.

CWE-78: Improper Neutralization of Special Elements used in an OS Command – CVE-2014-0356
The detectWeather(), set_language(), SystemCommand(), and NTPSyncWithHost() functions in management.c are reported to be vulnerable to command injection.

The udps commands SET COUNTRY, SET WLAN SSID, SET WLAN CHANNEL, SET WLAN STATUS, SET WLAN COUNTRY are reported to be vulnerable to command injection. The udps process is only accessible from the LAN side.

The CVSS score below was calculated for CVE-2014-0356.

Impact
A remote unauthenticated attacker on the local area network may be able to inject arbitrary commands or run arbitrary code.

Solution
We are currently unaware of a practical solution to this problem. Please consider the following workarounds.
Restrict Access
As a general good security practice, only allow connections from trusted hosts and networks. Do not enable remote management of the device on the WAN interface.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate UpdatedZyXELAffected23 Jan 201410 Mar 2014If you are a vendor and your product is affected, let
us know.

CVSS Metrics (Learn More)

Group
Score
Vector

Base
7.9
AV:A/AC:M/Au:N/C:C/I:C/A:C

Temporal
5.7
E:U/RL:W/RC:UC

Environmental
5.7
CDP:ND/TD:H/CR:ND/IR:ND/AR:ND

References

http://www.zyxel.com/
https://cwe.mitre.org/data/definitions/425.html
https://cwe.mitre.org/data/definitions/259.html
https://cwe.mitre.org/data/definitions/121.html
https://cwe.mitre.org/data/definitions/78.html

Credit

Thanks to the reporter who wishes to remain anonymous for reporting this vulnerability.
This document was written by Jared Allar.

Other Information

CVE IDs:
CVE-2014-0353
CVE-2014-0354
CVE-2014-0355
CVE-2014-0356

Date Public:
10 Mar 2014

Date First Published:
11 Apr 2014

Date Last Updated:
16 Apr 2014

Document Revision:
22

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