# CVE-2018-16841: ctdb: Samba from version 4.3.0 and before versions 4.7.12, 4.8.7 and 4.9.3 are vulnerable to a denial of service CVE-2018-16841 is fixed in 17 products on 1 platform, first by ctdb 2:4.7.6+dfsg~ubuntu-0ubuntu2.5, released November 26, 2018. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2018-16841 - Priority: Routine - CVSS: n/a (Medium) - EPSS: 0.0459 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Nov 26, 2018 ## Description Samba from version 4.3.0 and before versions 4.7.12, 4.8.7 and 4.9.3 are vulnerable to a denial of service. When configured to accept smart-card authentication, Samba's KDC will call talloc_free() twice on the same memory if the principal in a validly signed certificate does not match the principal in the AS-REQ. This is only possible after authentication with a trusted certificate. talloc is robust against further corruption from a double-free with talloc_free() and directly calls abort(), terminating the KDC process. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | ctdb Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [ctdb 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-ctdb-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libnss-winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libnss-winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnss-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libpam-winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libpam-winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libpam-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libparse-pidl-perl Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libparse-pidl-perl 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libparse-pidl-perl-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libsmbclient Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libsmbclient 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libsmbclient-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | libwbclient0 Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [libwbclient0 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libwbclient0-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | python-samba Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [python-samba 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-samba-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | registry-tools Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [registry-tools 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-registry-tools-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-common Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-common 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-common-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-common-bin Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-common-bin 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-common-bin-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-dsdb-modules Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-dsdb-modules 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-dsdb-modules-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-libs Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-libs 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-libs-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-testsuite Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-testsuite 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-testsuite-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | samba-vfs-modules Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [samba-vfs-modules 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-samba-vfs-modules-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | smbclient Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [smbclient 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-smbclient-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | | Linux | winbind Ubuntu 18.04.6 LTS (bionic) | 2:4.7.6+dfsg~ubuntu-0ubuntu2.5 | [winbind 2:4.7.6+dfsg~ubuntu-0ubuntu2.5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-winbind-2-4.7.6-dfsg-ubuntu-0ubuntu2.5.md) | Nov 26, 2018 | --- Data as of 2026-11-07T18:46:35Z UTC. 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