Description
If the source for resources on a page is through an FTP connection, it is possible to trigger a series of modal alert messages for these resources through invalid credentials or locations. These messages cannot be immediately dismissed, allowing for a denial of service (DOS) attack. This vulnerability affects Firefox < 66.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 66 | 66 |
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | mozjs52 | No fix yet | — |
| Ubuntu 18.04 LTS | firefox | 66.0+build3-0ubuntu0.18.04.1 | USN-3918-1 |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
| Ubuntu 16.04 LTS | firefox | 66.0+build3-0ubuntu0.16.04.2 | USN-3918-1 |
| Ubuntu 14.04 LTS | firefox | 66.0.1+build1-0ubuntu0.14.04.1 | USN-3918-2 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
Advisories 4
- USN-3918-2 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3918-1 firefox vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 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