CVE-2014-7278 DoS in ZyXEL SBG-3300 Security Gateway

2014-10-05T00:00:00
ID SECURITYVULNS:DOC:31127
Type securityvulns
Reporter Securityvulns
Modified 2014-10-05T00:00:00

Description

Vulnerability Title: DoS in ZyXEL SBG-3300 Security Gateway

Date: 02/10/2014

CVE-ID: CVE-2014-7278

Product: ZyXEL SBG3300-N series

Vendor: www.zyxel.com

Affected Firmware: Latest version at the time of disclosure V1.00(AADY.4)C0 and below (tested)

Patch: Unpatched

Authored by: Mirko Casadei

Disclosure Timeline:

13/08/2014 Vendor Contact with Acknowledgment 13/09/2014 No response from Vendor after first contact 02/10/2014 Full Disclosure

Technical details:

Abusing the 'welcome message' form, an attacker can inject JavaScript code into a core function of the main login page. The persistent javascript code injection in the framLoad() function bypass all the security checks and cause a Denial of Service disabling any access to the router web interface. Access is restored with a new firmware installation. Example of a working code: //////// !WARNING! TEST AT YOUR OWN RISK /////// var loginMsg loads input from the 'welcome message form' .. function framLoad () { var status = '0'; var count = ''; var Retry = ''; var period = '';
var loginMsg = '<DoS="javascript:alert('DoS coming!')">';
var LockTime; var waitTime; if ( advancedaccountsecurity == '0' ) { loginrandom = '0'; } ..

Remediation

The vulnerable form should sanitize input.