Description
In the client side of Heimdal before 7.6.0, failure to verify anonymous PKINIT PA-PKINIT-KX key exchange permits a man-in-the-middle attack. This issue is in krb5_init_creds_step in lib/krb5/init_creds_pw.c.
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 | heimdal | 7.5.0+dfsg-3 | — |
| Debian 13 | heimdal | 7.5.0+dfsg-3 | — |
| Debian 12 | heimdal | 7.5.0+dfsg-3 | — |
| Debian 9 | heimdal | 7.1.0+dfsg-13+deb9u3 | DSA-4455-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | heimdal | 7.7.0+dfsg-1ubuntu1.1 | USN-5675-1 |
| Ubuntu 18.04 LTS | heimdal | 7.5.0+dfsg-1ubuntu0.1 | USN-5675-1 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 16.04 LTS | heimdal | 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm1 | USN-5675-1 |
| Ubuntu Pro 14.04 LTS | heimdal | 1.6~git20131207+dfsg-1ubuntu1.2+esm1 | USN-5675-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP1 | libheimdal | 7.7.0-bp151.4.3.1 | openSUSE-SU-2019:1888-1 |
| SUSE Package Hub 15 | libheimdal | 7.7.0-bp150.2.3.1 | openSUSE-SU-2019:1688-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.1 | libheimdal | 7.7.0-lp151.3.3.1 | openSUSE-SU-2019:1682-1 |
| openSUSE Leap 15.0 | libheimdal | 7.7.0-lp151.3.3.1 | openSUSE-SU-2019:1682-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.10 | heimdal | 7.5.0-r5 | — |
| Alpine v3.9 | heimdal | 7.5.0-r4 | — |
| Alpine v3.8 | heimdal | 7.5.0-r3 | — |
| Alpine v3.7 | heimdal | 7.4.0-r4 | — |
Advisories 5
- USN-5675-1 heimdal vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- DSA-4455-1 heimdal - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2019:1688-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1888-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2019:1682-1 Security update for libheimdal SUSE / openSUSE Security Updates · May 7, 2025
References
- https://github.com/heimdal/heimdal/releases/tag/heimdal-7.6.0
- http://www.h5l.org/pipermail/heimdal-announce/2019-May/000009.html
- https://github.com/heimdal/heimdal/commit/2f7f3d9960aa6ea21358bdf3687cee5149aa35cf
- https://github.com/heimdal/heimdal/compare/3e58559...bbafe72
- 20190603 [SECURITY] [DSA 4455-1] heimdal security update mailing-list
- DSA-4455 vendor-advisory
- openSUSE-SU-2019:1682 vendor-advisory
- openSUSE-SU-2019:1688 vendor-advisory
- openSUSE-SU-2019:1888 vendor-advisory
- FEDORA-2019-f3046b6bfb vendor-advisory
- FEDORA-2019-2fa7d6405b vendor-advisory