Description
A flaw was found in samba's Heimdal KDC implementation, versions 4.8.x up to, excluding 4.8.12, 4.9.x up to, excluding 4.9.8 and 4.10.x up to, excluding 4.10.3, when used in AD DC mode. A man in the middle attacker could use this flaw to intercept the request to the KDC and replace the user name (principal) in the request with any desired user name (principal) that exists in the KDC effectively obtaining a ticket for that principal.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| SAMBA | samba | 4.8.x up to, excluding 4.8.12, 4.9.x up to, excluding 4.9.8, 4.10.x up to, excluding 4.10.3 | — |
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 14 | samba | 2:4.9.5+dfsg-4 | — |
| Debian 13 | heimdal | 7.5.0+dfsg-3 | — |
| Debian 13 | samba | 2:4.9.5+dfsg-4 | — |
| Debian 12 | heimdal | 7.5.0+dfsg-3 | — |
| Debian 12 | samba | 2:4.9.5+dfsg-4 | — |
| Debian 9 | heimdal | 7.1.0+dfsg-13+deb9u3 | DSA-4455-1 |
| Debian 9 | samba | 2:4.5.16+dfsg-1+deb9u2 | DSA-4443-1 |
| Debian 8 | samba | 2:4.2.14+dfsg-0+deb8u13 | DLA-1788-1 |
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 |
| Ubuntu 18.04 LTS | samba | 2:4.7.6+dfsg~ubuntu-0ubuntu2.10 | USN-3976-1 |
| Ubuntu 16.04 LTS | samba | 2:4.3.11+dfsg-0ubuntu0.16.04.20 | USN-3976-1 |
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 |
| Ubuntu Pro 14.04 LTS | samba | 2:4.3.11+dfsg-0ubuntu0.14.04.20+esm1 | USN-3976-2 |
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 Tumbleweed | samba | 4.14.6+git.182.2205d5224e3-1.1 | openSUSE-SU-2024:11365-1 |
| 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 v3.24 | heimdal | 7.5.3-r4 | — |
| Alpine v3.24 | samba | 4.10.3-r0 | — |
| Alpine v3.23 | heimdal | 7.5.3-r4 | — |
| Alpine v3.23 | samba | 4.10.3-r0 | — |
| Alpine v3.22 | heimdal | 7.5.3-r4 | — |
| Alpine v3.22 | samba | 4.10.3-r0 | — |
| Alpine v3.21 | heimdal | 7.5.3-r4 | — |
| Alpine v3.21 | samba | 4.10.3-r0 | — |
| Alpine v3.20 | heimdal | 7.5.3-r4 | — |
| Alpine v3.20 | samba | 4.10.3-r0 | — |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | heimdal | 7.5.3-r4 | — |
| Alpine v3.19 | samba | 4.10.3-r0 | — |
| Alpine v3.18 | heimdal | 7.5.3-r4 | — |
| Alpine v3.18 | samba | 4.10.3-r0 | — |
| Alpine v3.17 | heimdal | 7.5.3-r4 | — |
| Alpine v3.17 | samba | 4.10.3-r0 | — |
| Alpine v3.16 | heimdal | 7.5.3-r4 | — |
| Alpine v3.16 | samba | 4.10.3-r0 | — |
| Alpine v3.15 | heimdal | 7.5.3-r4 | — |
| Alpine v3.15 | samba | 4.10.3-r0 | — |
| Alpine v3.14 | heimdal | 7.5.3-r4 | — |
| Alpine v3.14 | samba | 4.10.3-r0 | — |
| Alpine v3.13 | heimdal | 7.5.3-r4 | — |
| Alpine v3.13 | samba | 4.10.3-r0 | — |
| Alpine v3.12 | heimdal | 7.5.3-r4 | — |
| Alpine v3.12 | samba | 4.10.3-r0 | — |
| Alpine v3.11 | heimdal | 7.5.3-r4 | — |
| Alpine v3.11 | samba | 4.10.3-r0 | — |
| Alpine v3.10 | heimdal | 7.5.0-r4 | — |
| Alpine v3.10 | samba | 4.10.3-r0 | — |
| Alpine v3.9 | heimdal | 7.5.0-r3 | — |
| Alpine v3.9 | samba | 4.8.12-r0 | — |
| Alpine v3.8 | heimdal | 7.5.0-r2 | — |
| Alpine v3.8 | samba | 4.8.12-r0 | — |
| Alpine v3.7 | heimdal | 7.4.0-r3 | — |
Advisories 10
- USN-5675-1 heimdal vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-3976-2 samba vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3976-1 samba vulnerability Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4455-1 heimdal - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-4443-1 samba - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1788-1 samba - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:11365-1 ctdb-4.14.6+git.182.2205d5224e3-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 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://www.synology.com/security/advisory/Synology_SA_19_23
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16860
- https://www.samba.org/samba/security/CVE-2018-16860.html
- 20190814 APPLE-SA-2019-8-13-2 Additional information for APPLE-SA-2019-7-22-1 iOS 12.4 mailing-list
- 20190814 APPLE-SA-2019-8-13-3 Additional information for APPLE-SA-2019-7-22-4 watchOS 5.3 mailing-list
- 20190814 APPLE-SA-2019-8-13-4 Additional information for APPLE-SA-2019-7-22-5 tvOS 12.4 mailing-list
- 20190814 APPLE-SA-2019-8-13-1 Additional information for APPLE-SA-2019-7-22-2 macOS Mojave 10.14.6, Security Update 2019-004 High Sierra, Security Update 2019-004 Sierra mailing-list
- openSUSE-SU-2019:1888 vendor-advisory
- 20190816 APPLE-SA-2019-8-13-3 Additional information for APPLE-SA-2019-7-22-4 watchOS 5.3 mailing-list
- 20190816 APPLE-SA-2019-8-13-1 Additional information for APPLE-SA-2019-7-22-2 macOS Mojave 10.14.6, Security Update 2019-004 High Sierra, Security Update 2019-004 Sierra mailing-list
- 20190816 APPLE-SA-2019-8-13-2 Additional information for APPLE-SA-2019-7-22-1 iOS 12.4 mailing-list
- 20190816 APPLE-SA-2019-8-13-4 Additional information for APPLE-SA-2019-7-22-5 tvOS 12.4 mailing-list
- https://support.apple.com/HT210346
- https://support.apple.com/HT210348
- https://support.apple.com/HT210351
- https://support.apple.com/HT210353
- GLSA-202003-52 vendor-advisory