Description
Mozilla Firefox 3.0.x before 3.0.18 and 3.5.x before 3.5.8, and SeaMonkey before 2.0.3, does not properly restrict read access to object properties in showModalDialog, which allows remote attackers to bypass the Same Origin Policy and conduct cross-site scripting (XSS) attacks via crafted dialogArguments values.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 5.0 | xulrunner | 1.9.0.18-1 | DSA-1999-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | firefox | 3.0.18-1.el5_4 | RHSA-2010:0112 |
| RHEL 5 | xulrunner +2 | 1.9.0.18-1.el5_4 | RHSA-2010:0112 |
| RHEL 4 | firefox | 3.0.18-1.el4 | RHSA-2010:0112 |
Advisories 2
- RHSA-2010:0112 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1999-1 xulrunner - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
References
- USN-895-1 vendor-advisory
- 38847 third-party-advisory
- SUSE-SA:2010:015 vendor-advisory
- MDVSA-2010:042 vendor-advisory
- FEDORA-2010-1936 vendor-advisory
- RHSA-2010:0112 vendor-advisory
- FEDORA-2010-1932 vendor-advisory
- oval:org.mitre.oval:def:8355 vdb-entry signature
- DSA-1999 vendor-advisory
- FEDORA-2010-1727 vendor-advisory
- mozilla-showmodaldialog-xss(56362) vdb-entry
- USN-896-1 vendor-advisory
- ADV-2010-0405 vdb-entry
- 37242 third-party-advisory
- oval:org.mitre.oval:def:9384 vdb-entry signature
- http://www.mozilla.org/security/announce/2010/mfsa2010-04.html
- https://bugzilla.mozilla.org/show_bug.cgi?id=504862