Description
The Mozilla Maintenance Service granted SERVICE_START access to BUILTIN|Users which, in a domain network, grants normal remote users access to start or stop the service. This could be used to prevent the browser update service from operating (if an attacker spammed the 'Stop' command); but also exposed attack surface in the maintenance service. *Note: This issue only affected Windows operating systems older than Win 10 build 1709. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 78.10.1, Firefox < 87, and Firefox ESR < 78.10.1.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Mozilla | Thunderbird | unspecified – < 78.10.1 | 78.10.1 |
| Mozilla | Firefox | unspecified – < 87 | 87 |
| Mozilla | Firefox ESR | unspecified – < 78.10.1 | 78.10.1 |
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.
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | MozillaFirefox | 78.11.0-8.43.1 | SUSE-SU-2021:1884-1 |
| SLES 15 SP3 | MozillaThunderbird | 78.10.2-8.27.1 | SUSE-SU-2021:1854-1 |
| SLES 15 SP2 | MozillaFirefox | 78.11.0-8.43.1 | SUSE-SU-2021:1884-1 |
| SLES 15 SP2 | MozillaThunderbird | 78.10.2-8.27.1 | SUSE-SU-2021:1854-1 |
| SLES 15 SP1 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SLES 15 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SLES 12 SP5 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
Show 20 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP4 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLES 12 SP3 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLES 12 SP2 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLES 11 SP4 | MozillaFirefox | 78.11.0-78.131.1 | SUSE-SU-2021:14743-1 |
| SLES for SAP 15 SP1 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SLES for SAP 15 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SLES for SAP 12 SP5 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLES for SAP 12 SP4 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLES for SAP 12 SP3 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SLE HPC 15 SP1 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SLE HPC 15 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SUSE OpenStack Cloud Crowbar 9 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SUSE OpenStack Cloud Crowbar 8 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SUSE OpenStack Cloud 9 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SUSE OpenStack Cloud 8 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SUSE Manager Server 4.0 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SUSE Manager Retail Branch Server 4.0 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SUSE Manager Proxy 4.0 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
| SUSE HPE Helion OpenStack 8 | MozillaFirefox | 78.11.0-112.62.1 | SUSE-SU-2021:1886-1 |
| SUSE Enterprise Storage 6 | MozillaFirefox | 78.11.0-3.144.1 | SUSE-SU-2021:1919-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.3 | MozillaFirefox | 78.11.0-8.43.1 | openSUSE-SU-2021:1884-1 |
| openSUSE Leap 15.3 | MozillaThunderbird | 78.10.2-8.27.1 | openSUSE-SU-2021:1854-1 |
| openSUSE Leap 15.2 | MozillaFirefox | 78.11.0-lp152.2.58.1 | openSUSE-SU-2021:0858-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.23 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.22 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.21 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.20 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.19 | thunderbird | 91.3.2-r0 | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.18 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.17 | thunderbird | 91.3.2-r0 | — |
| Alpine v3.16 | thunderbird | 91.3.2-r0 | — |
Advisories 8
- SUSE-SU-2021:1854-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1884-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1886-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1919-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1884-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1854-1 Security update for MozillaThunderbird SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0858-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14743-1 Security update for MozillaFirefox SUSE / openSUSE Security Updates · May 2, 2025