Mozilla Firefox CSS Cursor Image heap-based overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.

A vulnerability classified as critical has been found in Mozilla Firefox (Web Browser). Affected is an unknown function of the component CSS Cursor Image Handler. The manipulation with an unknown input leads to a heap-based overflow vulnerability. CWE is classifying the issue as CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Heap-based buffer overflow in Mozilla Firefox 2.x before, 1.5.x before, Thunderbird before, and SeaMonkey before 1.0.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code by setting the CSS cursor to certain images that cause an incorrect size calculation when converting to a Windows bitmap.

The weakness was disclosed 12/19/2006 by Igor Bukanov, Jesse Ruderman and moz_bug_r_a4 as MFSA2006-69 as confirmed advisory (Website). The advisory is shared for download at This vulnerability is traded as CVE-2006-6500 since 12/13/2006. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

It is declared as proof-of-concept. The vulnerability scanner Nessus provides a plugin with the ID 23991 (GLSA-200701-02 : Mozilla Firefox: Multiple vulnerabilities), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Gentoo Local Security Checks. The commercial vulnerability scanner Qualys is able to test this issue with plugin 165111 (SUSE Security Update for Mozilla Firefox, Mozilla Thunderbird (SUSE-SA:2006:080)).

Upgrading eliminates this vulnerability. Applying a patch is able to eliminate this problem. The bugfix is ready for download at The best possible mitigation is suggested to be upgrading to the latest version. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 9089.

The vulnerability is also documented in the databases at X-Force (30987) and Tenable (23991). The entries 2774, 2770, 2771 and 2777 are pretty similar.







CPE 2.3info

CPE 2.2info


VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍


VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 5.7

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍



VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍


Class: Heap-based overflow
CWE: CWE-122 / CWE-119
ATT&CK: Unknown

Local: No
Remote: Yes

Availability: 🔍
Status: Proof-of-Concept

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍


Nessus ID: 23991
Nessus Name: GLSA-200701-02 : Mozilla Firefox: Multiple vulnerabilities
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍

OpenVAS ID: 830140
OpenVAS Name: Zoho ManageEngine Support Center Plus Multiple Fields XSS Vulnerabilities
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍


Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

TippingPoint: 🔍


12/13/2006 🔍
12/19/2006 +6 days 🔍
12/19/2006 +0 days 🔍
12/19/2006 +0 days 🔍
12/19/2006 +0 days 🔍
12/19/2006 +0 days 🔍
12/19/2006 +0 days 🔍
12/20/2006 +0 days 🔍
12/21/2006 +1 days 🔍
03/13/2021 +5196 days 🔍



Advisory: MFSA2006-69
Researcher: Igor Bukanov, Jesse Ruderman, moz_bug_r_a4
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2006-6500 (🔍)
X-Force: 30987
SecurityTracker: 1017401 - Mozilla Firefox Windows Cursor Image Conversion Heap Overflow Lets Remote Users Execute Arbitrary Code
Vulnerability Center: 13424 - Mozilla Web-Browsers Buffer Overflow via CSS Cursor, Medium
SecurityFocus: 21668 - Mozilla Firefox/SeaMonkey/Thunderbird Multiple Remote Vulnerabilities
Secunia: 23282 - Mozilla Firefox Multiple Vulnerabilities, Highly Critical
OSVDB: 31345 - Mozilla Multiple Products on Windows CSS Cursor Image Overflow
Vupen: ADV-2006-5068

See also: 🔍


Created: 12/21/2006 10:15 AM
Updated: 03/13/2021 05:52 PM
Changes: 12/21/2006 10:15 AM (86), 01/31/2018 09:53 AM (10), 03/13/2021 05:52 PM (2)
Complete: 🔍


No comments yet. Languages: en.

Please log in to comment.

Interested in the pricing of exploits?

See the underground prices here!