What’s Vulnerable › Vulnerabilities

CVE-2006-6503

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 4.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2006-12-20 · updated 2026-06-16
• Weakness: CWE-254

Description

Mozilla Firefox 2.x before 2.0.0.1, 1.5.x before 1.5.0.9, Thunderbird before 1.5.0.9, and SeaMonkey before 1.0.7 allows remote attackers to bypass cross-site scripting (XSS) protection by changing the src attribute of an IMG element to a javascript: URI.

Affected products

• Canonical Ubuntu Linux: 5.10, 6.06, 6.10
• Debian Linux: 3.1, 4.0
• Mozilla Firefox: from 1.5 before 1.5.0.9; from 2.0 before 2.0.0.1 — fixed in 1.5.0.9, 2.0.0.1
• Mozilla Seamonkey: before 1.0.7 — fixed in 1.0.7
• Mozilla Thunderbird: before 1.5.0.9 — fixed in 1.5.0.9

How to fix

Upgrade to a fixed version: Mozilla Firefox 1.5.0.9, 2.0.0.1; Mozilla Seamonkey 1.0.7; Mozilla Thunderbird 1.5.0.9. Check the vendor advisory for mitigations.

References

• http://fedoranews.org/cms/node/2297
• http://fedoranews.org/cms/node/2338
• http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00771742
• http://rhn.redhat.com/errata/RHSA-2006-0758.html
• http://rhn.redhat.com/errata/RHSA-2006-0759.html
• http://rhn.redhat.com/errata/RHSA-2006-0760.html
• http://secunia.com/advisories/23282
• http://secunia.com/advisories/23420
• http://secunia.com/advisories/23422
• http://secunia.com/advisories/23433
• http://secunia.com/advisories/23439

Get alerted when CVE-2006-6503 or the next vulnerability affects your stack