Description
If a user downloaded a file lacking an extension on Windows, and then "Open"-ed it from the downloads panel, if there was an executable file in the downloads directory with the same name but with an executable extension (such as .bat or .exe) that executable would have been launched instead. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Firefox | unspecified – < 84 | 84 |
| Mozilla | Thunderbird | unspecified – < 78.6 | 78.6 |
| Mozilla | Firefox ESR | unspecified – < 78.6 | 78.6 |
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 22.04 LTS | mozjs78 | No fix yet | — |
| Ubuntu 20.04 LTS | mozjs52 +1 | No fix yet | — |
| Ubuntu 18.04 LTS | mozjs38 +1 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | MozillaFirefox | 78.6.0-8.20.2 | SUSE-SU-2020:3901-1 |
| SLES 15 SP2 | MozillaThunderbird | 78.6.0-8.3.1 | SUSE-SU-2020:3935-1 |
| SLES 15 SP1 | MozillaFirefox | 78.6.0-3.122.1 | SUSE-SU-2020:3902-1 |
| SLES 15 SP1 | MozillaThunderbird | 78.6.0-3.113.1 | SUSE-SU-2020:3900-1 |
| SLES 12 SP5 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES 12 SP4 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES 12 SP3 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES 11 SP4 | MozillaFirefox | 78.6.0-78.108.1 | SUSE-SU-2020:14584-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SLES for SAP 12 SP2 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE OpenStack Cloud 7 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
| SUSE Enterprise Storage 5 | MozillaFirefox | 78.6.0-112.39.1 | SUSE-SU-2020:3903-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | MozillaFirefox | 92.0-1.2 | openSUSE-SU-2024:10600-1 |
| openSUSE Tumbleweed | MozillaThunderbird | 91.1.1-1.1 | openSUSE-SU-2024:10601-1 |
| openSUSE Tumbleweed | firefox-esr | 128.5.1-1.1 | openSUSE-SU-2024:14572-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.6.0-lp152.2.34.1 | openSUSE-SU-2020:2318-1 |
| openSUSE Leap 15.2 | MozillaThunderbird | 78.6.0-lp152.2.23.1 | openSUSE-SU-2020:2317-1 |
| openSUSE Leap 15.1 | MozillaFirefox | 78.6.0-lp151.2.82.1 | openSUSE-SU-2020:2325-1 |
| openSUSE Leap 15.1 | MozillaThunderbird | 78.6.0-lp151.2.63.1 | openSUSE-SU-2020:2324-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | librewolf | 84.0.1-r0 | — |
| Alpine v3.23 | firefox +1 | 84.0.1-r0 | — |
| Alpine v3.23 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.23 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.22 | firefox +1 | 84.0.1-r0 | — |
| Alpine v3.22 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.22 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.21 | firefox +1 | 84.0.1-r0 | — |
| Alpine v3.21 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.21 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.20 | firefox | 84.0.1-r0 | — |
| Alpine v3.20 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.20 | thunderbird | 78.6.1-r0 | — |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | firefox | 84.0.1-r0 | — |
| Alpine v3.19 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.19 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.18 | firefox | 84.0.1-r0 | — |
| Alpine v3.18 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.18 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.17 | firefox | 84.0.1-r0 | — |
| Alpine v3.17 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.17 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.16 | firefox | 84.0.1-r0 | — |
| Alpine v3.16 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.16 | thunderbird | 78.6.1-r0 | — |
| Alpine v3.15 | firefox | 84.0.1-r0 | — |
| Alpine v3.15 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.14 | firefox | 84.0.1-r0 | — |
| Alpine v3.14 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.13 | firefox | 84.0.1-r0 | — |
| Alpine v3.13 | firefox-esr | 78.6.0-r0 | — |
| Alpine v3.12 | firefox | 84.0.1-r0 | — |
| Alpine v3.12 | firefox-esr | 78.6.0-r0 | — |
Advisories 13
- SUSE-SU-2020:14584-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2317-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2325-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10600-1 MozillaFirefox-92.0-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3935-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3903-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2324-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3900-1 Security update for MozillaThunderbird 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
- SUSE-SU-2020:3902-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2318-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 7, 2025
- openSUSE-SU-2024:10601-1 MozillaThunderbird-91.1.1-1.1 on GA media SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2020:3901-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 2, 2025