Description
Heimdal 0.6.x before 0.6.1 and 0.5.x before 0.5.3 does not properly perform certain consistency checks for cross-realm requests, which allows remote attackers with control of a realm to impersonate others in the cross-realm trust path.
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 | 0.6.1-1 | — |
| Debian 13 | heimdal | 0.6.1-1 | — |
| Debian 12 | heimdal | 0.6.1-1 | — |
| Debian 3.0 | heimdal | 0.4e-7.woody.8.1 | DSA-476 |
Advisories 1
- DSA-476 heimdal - cross-realm Debian Security (DSA / DLA) · Mar 9, 2026
References
- GLSA-200404-09 vendor-advisory
- heimdal-cross-realm-spoofing(15701) vdb-entry
- DSA-476 vendor-advisory
- http://www.pdc.kth.se/heimdal/advisory/2004-04-01/