Description
Mozilla Firefox 3.5.x before 3.5.11 and 3.6.x before 3.6.7, Thunderbird 3.0.x before 3.0.6 and 3.1.x before 3.1.1, and SeaMonkey before 2.0.6 permit cross-origin loading of CSS stylesheets even when the stylesheet download has an incorrect MIME type and the stylesheet document is malformed, which allows remote attackers to obtain sensitive information via a crafted document.
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 | 1.9.0.19-3 | DSA-2124-1, DSA-2075-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | firefox | 3.6.7-2.el5 | RHSA-2010:0547 |
| RHEL 5 | xulrunner +1 | 1.9.2.7-2.el5 | RHSA-2010:0547 |
| RHEL 4 | firefox | 3.6.7-2.el4 | RHSA-2010:0547 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 50.1.0-1.1 | openSUSE-SU-2024:10071-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 45.5.1-1.1 | openSUSE-SU-2024:10230-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Advisories 6
- RHSA-2010:0547 Red Hat Security Advisory: firefox security update Red Hat Security Advisories (RHSA) · Jun 28, 2026
- DSA-2075-1 xulrunner - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-2124-1 xulrunner - several vulnerabilities Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10230-1 MozillaThunderbird-45.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:14572-1 firefox-esr-128.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10071-1 MozillaFirefox-50.1.0-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- http://scarybeastsecurity.blogspot.com/2009/12/generic-cross-browser-cross-domain.html
- http://websec.sv.cmu.edu/css/css.pdf
- oval:org.mitre.oval:def:11811 vdb-entry signature
- https://bugzilla.mozilla.org/show_bug.cgi?id=524223
- http://code.google.com/p/chromium/issues/detail?id=9877
- http://www.mozilla.org/security/announce/2010/mfsa2010-46.html