Executive Summary

This Alert is flagged as TOP 25 Common Weakness Enumeration from CWE/SANS. For more information, you can read this.
Title Mozilla Firefox URL protocol handling vulnerability
Name VU#358017 First vendor Publication 2007-07-11
Vendor VU-CERT Last vendor Modification 2007-07-19
Severity (Vendor) N/A Revision M

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:N/AC:M/Au:N/C:N/I:P/A:N)
Cvss Base Score 4.3 Attack Range Network
Cvss Impact Score 2.9 Attack Complexity Medium
Cvss Expoit Score 8.6 Authentication None Required
Calculate full CVSS 2.0 Vectors scores


Vulnerability Note VU#358017

Mozilla Firefox URL protocol handling vulnerability


Mozilla Firefox protocol handlers may allow remotely supplied JavaScript to execute with elevated privileges. This may allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

On Microsoft Windows systems, Mozilla Firefox installs protocol handlers for Mozilla-specific protocols, such as the FirefoxURL and FirefoxHTML protocols. If Microsoft Windows encounters a URL protocol it cannot handle natively it searches the Windows registry for the appropriate protocol handler. When the correct protocol handler is found, Windows passes it the URL string. By design Windows passes the URL string to the protocol handler as it was received without performing any sanitization.

Mozilla Firefox URL protocol handlers are constructed in a way that may allow a remote attacker to execute arbitrary JavaScript with elevated (chrome) privileges. Mozilla Firefox security restrictions detect and prevent the execution of such JavaScript. However, if a remote attacker can persuade a user with Firefox installed to access a specially crafted web page using Internet Explorer, and perhaps other Windows applications, the malicious JavaScript will be executed. Reports claim this vulnerability is introduced when Firefox versions and later are installed.

Exploit code is publicly available for this vulnerability.

II. Impact

This vulnerability may allow a remote, unauthenticated attacker to execute JavaScript with elevated (chrome) privileges. This essentially means that the attacker can execute arbitrary code with the privileges of the user.

III. Solution


Mozilla has addressed this vulnerability in Firefox

Unregister the Firefox protocols

Disabling the Mozilla Firefox protocol handlers will mitigate this vulnerability. To unregister the protocol handlers, delete or rename the following registry keys:

Modifying the Windows registry may have unintended consequences and should be done with care.

Systems Affected

VendorStatusDate Updated
Microsoft CorporationUnknown10-Jul-2007




This vulnerability was publicly disclosed by Thor Larholm.

This document was written by Jeff Gennari.

Other Information

Date Public07/10/2007
Date First Published07/11/2007 10:53:35 AM
Date Last Updated07/19/2007
CERT Advisory 
CVE NameCVE-2007-3670
Document Revision65

Original Source

Url : http://www.kb.cert.org/vuls/id/358017

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-79 Failure to Preserve Web Page Structure ('Cross-site Scripting') (CWE/SANS Top 25)

CPE : Common Platform Enumeration

Application 6
Application 1

OpenVAS Exploits

Date Description
2009-10-10 Name : SLES9: Security update for Mozilla
File : nvt/sles9p5011293.nasl
2009-05-05 Name : HP-UX Update for Thunderbird HPSBUX02156
File : nvt/gb_hp_ux_HPSBUX02156.nasl
2009-04-09 Name : Mandriva Update for mozilla-firefox MDKSA-2007:152 (mozilla-firefox)
File : nvt/gb_mandriva_MDKSA_2007_152.nasl
2009-03-23 Name : Ubuntu Update for mozilla-thunderbird vulnerabilities USN-503-1
File : nvt/gb_ubuntu_USN_503_1.nasl
2009-01-28 Name : SuSE Update for MozillaFirefox,MozillaThunderbird,Seamonkey SUSE-SA:2007:049
File : nvt/gb_suse_2007_049.nasl

Open Source Vulnerability Database (OSVDB)

Id Description
38017 Microsoft IE with Mozilla Firefox Cross-browser Command Execution

Nessus® Vulnerability Scanner

Date Description
2009-02-16 Name : The remote host contains a web browser that is prone to a cross- browser scri...
File : google_chrome_1_0_154_48.nasl - Type : ACT_GATHER_INFO
2007-12-13 Name : The remote SuSE 10 host is missing a security-related patch.
File : suse_MozillaFirefox-3932.nasl - Type : ACT_GATHER_INFO
2007-11-10 Name : The remote Ubuntu host is missing one or more security-related patches.
File : ubuntu_USN-503-1.nasl - Type : ACT_GATHER_INFO
2007-10-17 Name : The remote openSUSE host is missing a security update.
File : suse_MozillaFirefox-3933.nasl - Type : ACT_GATHER_INFO
2007-10-17 Name : The remote openSUSE host is missing a security update.
File : suse_MozillaFirefox-3935.nasl - Type : ACT_GATHER_INFO
2007-10-17 Name : The remote openSUSE host is missing a security update.
File : suse_MozillaThunderbird-3973.nasl - Type : ACT_GATHER_INFO
2007-10-17 Name : The remote openSUSE host is missing a security update.
File : suse_seamonkey-3984.nasl - Type : ACT_GATHER_INFO
2007-10-17 Name : The remote openSUSE host is missing a security update.
File : suse_seamonkey-3986.nasl - Type : ACT_GATHER_INFO
2007-08-02 Name : The remote Mandrake Linux host is missing one or more security updates.
File : mandrake_MDKSA-2007-152.nasl - Type : ACT_GATHER_INFO