Description
In devs.c in Yubico libu2f-host before 1.1.8, the response to init is misparsed, leaking uninitialized stack memory back to the device.
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 14 | libu2f-host | 1.1.9-1 | — |
| Debian 13 | libu2f-host | 1.1.9-1 | — |
| Debian 12 | libu2f-host | 1.1.9-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libu2f-host | No fix yet | — |
| Ubuntu 16.04 LTS | libu2f-host | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | libu2f-host | 1.1.10-3.9.1 | SUSE-SU-2021:1755-1 |
| SLES 15 SP2 | libu2f-host | 1.1.10-3.9.1 | SUSE-SU-2021:1755-1 |
| SLES 15 SP1 | libu2f-host | 1.1.6-3.6.1 | SUSE-SU-2019:1750-1 |
| SLES 15 SP1 | pam_u2f | 1.0.8-3.3.1 | SUSE-SU-2019:1750-1 |
| SLES 15 | libu2f-host | 1.1.6-3.6.1 | SUSE-SU-2019:1750-1 |
| SLES 15 | pam_u2f | 1.0.8-3.3.1 | SUSE-SU-2019:1750-1 |
| SLES 12 SP4 | libu2f-host | 1.1.6-3.5.1 | SUSE-SU-2019:1749-1 |
| SLES 12 SP4 | pam_u2f | 1.0.8-3.3.1 | SUSE-SU-2019:1749-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP4 | libu2f-host | 1.1.6-3.5.1 | SUSE-SU-2019:1749-1 |
| SLES for SAP 12 SP4 | pam_u2f | 1.0.8-3.3.1 | SUSE-SU-2019:1749-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.3 | libu2f-host | 1.1.10-3.9.1 | openSUSE-SU-2021:1755-1 |
| openSUSE Leap 15.2 | libu2f-host | 1.1.10-lp152.4.3.1 | openSUSE-SU-2021:0799-1 |
| openSUSE Leap 15.1 | libu2f-host | 1.1.6-lp151.2.6.1 | openSUSE-SU-2019:1708-1 |
| openSUSE Leap 15.1 | pam_u2f | 1.0.8-lp151.2.3.1 | openSUSE-SU-2019:1708-1 |
| openSUSE Leap 15.0 | libu2f-host | 1.1.6-lp150.10.1 | openSUSE-SU-2019:1725-1 |
| openSUSE Leap 15.0 | pam_u2f | 1.0.8-lp150.7.1 | openSUSE-SU-2019:1725-1 |
Advisories 7
- openSUSE-SU-2021:1755-1 Security update for libu2f-host SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1749-1 Security update for libu2f-host SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2019:1750-1 Security update for libu2f-host, pam_u2f SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1708-1 Security update for libu2f-host, pam_u2f SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0799-1 Security update for libu2f-host SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1755-1 Security update for libu2f-host SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1725-1 Security update for libu2f-host, pam_u2f SUSE / openSUSE Security Updates · Feb 4, 2026
References
- https://developers.yubico.com/libu2f-host/Release_Notes.html
- https://github.com/Yubico/libu2f-host/commit/e4bb58cc8b6202a421e65f8230217d8ae6e16eb5
- FEDORA-2019-fe6d1fbffa vendor-advisory
- FEDORA-2019-4d83e78ad8 vendor-advisory
- openSUSE-SU-2019:1708 vendor-advisory
- openSUSE-SU-2019:1725 vendor-advisory
- https://blog.inhq.net/posts/yubico-libu2f-host-vuln-part2/
- GLSA-202004-15 vendor-advisory